Ling Yunguang: Building a platform for technology and products, multi-industry empowerment and intelligent manufacturing

  China Securities Network News (Wang Luo) started from the printing industry. Lingyun Guang has been deeply involved in the industrial machine vision industry for 20 years, and has expanded its applications to consumer electronics, new displays, new energy and other fields. Head enterprises in industries such as Apple, Huawei, Xiaomi, Foxconn, BOE and () are all important customers of Lingyun Guang.

  On June 15th, Ling Yunguang (stock code: 688400) officially launched the inquiry offering, and will soon land in science and technology innovation board. The science and technology innovation board listing, Lingyun Guang plans to raise 1.5 billion yuan, and the fundraising direction is centered on the company’s vision planning. From industrial manufacturing to industrial intelligent manufacturing, machine vision is promising. The company will increase investment in technology research and development, continuously improve its platform-based capabilities, empower intelligent manufacturing, and help more industries achieve automation and intelligent development. The company’s development vision is to implant "eyes" and "brains" into machines and become a global leader in the fields of visual artificial intelligence and photoelectric information.

  From agency to self-research, mastering the underlying core technology

  According to the prospectus, Ling Yunguang was established in 2002, and started from the banknote printing industry, and carried out independent research and development through projects such as online detection of RMB gravure printing and large sheet detection; On the other hand, the agency business of foreign high-end visual devices is carried out. Since 2006, the company has successively entered the fields of printing and packaging, new display and consumer electronics, and further improved its independent research and development capabilities. At present, it has the research and development capabilities of advanced imaging, intelligent algorithms, intelligent software and automatic precision control, and independently developed core devices such as industrial cameras and light sources, which are applied to many industries.

  The domestic machine vision started in the late 1990s. When Ling Yunguang entered this field 20 years ago, the domestic development and application were basically blank. The company started from scratch and gradually embarked on the road of independent research and development in the field of machine vision.

  Ling Yunguang attached great importance to self-research of core technologies at the early stage of business development. During the period from 2002 to 2006, the company initially built a 100-person team with independent research and development capabilities of optical, mechanical, electrical, computing and software technologies, and started the research and development of independent software algorithms of VisionWARE. The technical accumulation in this period has created an insurmountable moat for the company’s competitors in a short period of time. Now the machine VisionWARE algorithm platform independently developed by the company has been iterated to version 5.0. Ling Yunguang is the first machine vision manufacturer in China to launch a purely independent bottom-level core algorithm library. The investment cycle of the bottom-level algorithm is quite long. It takes a lot of time and experience to optimize the core algorithm from the bottom, which makes it ahead of competitors in the same industry for about three to five years.

  In addition, Ling Yunguang’s AI algorithm development based on deep learning, machine learning and knowledge map has also been at the forefront of the industry, forming an independent F.Brain intelligent algorithm platform, supporting factory-side and edge intelligence through edge computing, and supporting factory cloud intelligence through big data cloud computing technology. From the application point of view, the machine vision +AI technology is deeply combined to support industrial scenes.

  It is understood that the algorithm library of the machine vision industry consists of open source vision algorithm libraries such as OpenCV, and third-party commercial payment algorithm libraries such as Vision Pro (cognex, USA), Halcon (German MVTec) and VisionWare (Ling Yunguang). Due to the long development cycle and large investment of algorithm library, companies in the industry usually develop their own application algorithms based on open source algorithm library, or independently develop and integrate with third parties, and few companies develop the underlying algorithms completely independently.

  In addition to algorithms, Lingyun Guang has always been at the forefront of optical imaging technology, and has independently developed a series of visual core devices such as smart cameras and high-brightness special light sources. It has more than 70 patents in the optical field, and many solutions are the first to benchmark international and domestic machine vision friends, creating a brighter industrial "eye" competitiveness. At the same time, by investing in domestic CMOS sensor design company Changguang Chenxin and industrial lens professional company Hunan Changdao Optoelectronics, we will optimize the allocation of core resources and lay out the localization and autonomy of core technologies.

  Form platform capability from system to equipment

  After all, the banknote printing industry belongs to a special industry. After 2006, Ling Yunguang gradually expanded its business to printing and packaging, display screens, consumer electronics and other industries, and further integrated its research and development capabilities into platform-based capabilities of products and technologies, thus effectively supporting the company to achieve cross-industry development. In addition, the company began to expand its automation capability in 2016, and it took three years to gradually build automatic control technologies such as automatic assembly line and multi-axis precision manipulator.

  Up to now, Lingyun Guang has four technical platforms, including advanced imaging, intelligent algorithm, intelligent software and intelligent automation, and comprehensive overall scheme design capability. It has 418 domestic patents and 208 software copyrights, which supports the company’s rapid expansion of downstream industries from printing to other fields, such as consumer electronics and new energy, and is also a technical base to support the company’s continuous leap-forward development in the future.

  According to Ling Yunguang’s prospectus, up to now, the company has developed diversified intelligent visual equipment and innovative process solutions based on independent research and development of visual algorithms and AI algorithms for new display, consumer electronics, printing and packaging, new energy and other fields. Specific to the display field, the new display intelligent vision equipment products provided by Ling Yunguang can realize automatic and semi-automatic optical detection of small screen defects in TFT-LCD/OLED, covering the Cell process section and module process section, and support lighting detection when the screen is powered on and appearance detection when it is not powered on. The detection efficiency of the LCD lighting quality detector provided by it is more than 3 times that of manual work, which solves the problem of 2% low contrast stain defect detection, approaches the limit of human eyes, realizes high dynamic range detection, and has been popularized and applied in hundreds of sets in the industry.

  Entering Apple’s industrial chain is a key milestone for Ling Yunguang, and it is also the inevitable result of technical capacity building. Five years ago, the company broke the situation that the high-end market of consumer electronic vision inspection was monopolized by foreign manufacturers such as cognex and Kearns for a long time, and became the Preferred Supplier in the field of machine vision certified by Apple, and began to provide configurable vision systems in batches.

  "Hand", "Eye" and "Brain" cooperate to empower intelligent industrial production.

  If configurable vision system products, such as machine vision algorithm platform developed by Ling Yunguang, can equip industrial machines with eyes and brains, then intelligent vision equipment is to implant muscles and limbs controlled by brains into the machines, thus realizing the precise control and execution of detection and production technology, and finally forming an intelligent production robot with the cooperation of hands, eyes and brains.

  As the largest manufacturing country in the world, the penetration rate of domestic machine vision application is low, and there is still much room for growth, especially the aging population and the increase in labor costs, which also bring great demand to the machine vision industry.

  From the demand of downstream customers, the epidemic situation in COVID-19 is complicated in recent years. Instead of reducing the budget for technology investment, downstream manufacturers have been further forced by the epidemic to strengthen their investment in industrial automation, digitalization and intelligence, and the cost reduction effect is very remarkable. In the future, the demand of downstream manufacturers for automation and intelligence is rigid and inevitable.

  China market has become one of the fastest growing markets in the global machine vision market. According to the statistics of China Machine Vision Industry Alliance, the sales of machine vision industry in China increased from 10.18 billion yuan in 2018 to 14.42 billion yuan in 2020, with a compound growth rate of 19.02%. Thanks to the promotion of manufacturing automation and other factors, it is estimated that the sales of machine vision industry in China will increase at a compound growth rate of 27.15% from 2020 to 2023, and the sales will reach 29.6 billion yuan by 2023.

  Under such opportunities, Lingyun Guang will continue to promote technological innovation in advanced optical imaging, software and algorithms, automation and other fields, and actively explore new application fields of industrial machine vision. At present, Ling Yunguang’s machine vision +AI products and services have achieved a high market share in consumer electronics, display panels, printing and packaging applications. According to the statistics of China Machine Vision Industry Alliance, in 2020, among the enterprises participating in the statistics (enterprises within the alliance), Lingyun Guang ranked first in the sales of machine vision industry in China.

  According to the disclosure in the prospectus, the company is expanding its business to the field of new energy battery diaphragm detection, and has cooperated with customers such as Contemporary Amperex Technology Co., Limited. Focusing on the field of industrial manufacturing for 20 years, Lingyun Guang is expected to become the leader of industrial artificial intelligence, truly helping factories to improve quality, increase efficiency, reduce costs and reduce storage.

Just after double 11, Xiao Ye E-cigarette: All self-operated sales on the Internet have been completely stopped.

(Observer Network News/Lv Dong Editor/Yin Zhe)

On the evening of November 12th, vvild Xiao Ye officially issued a statement saying that it had completely stopped all self-operated sales on the Internet.

VVI ILD Xiao Ye said that Xiao Ye Science and Technology supported the relevant requirements of the State Administration of Markets and the State Tobacco Monopoly Bureau, and has taken the initiative to close online sales channels such as Tmall and JD.COM, deleted all online marketing content related to sales, and urged all non-self-operated social channels to stop online sales immediately.

VVI ILD Xiao Ye also said that it has strictly regulated the sales behavior of dealers when it goes online, and it is absolutely not allowed to recommend or sell e-cigarette products to minors.

Observer. com noticed on Tmall and JD.COM that keywords such as "Xiao Ye vvild" can no longer be searched.

Tmall screenshot

JD.COM screenshot

The following is the original statement of vvild Xiao Ye:

According to Xiao Ye official website, vvild, Xiao Ye is affiliated to Shenzhen Xiao Ye Technology Co., Ltd., and the founding team of Xiao Ye is from well-known brands such as Huawei and Hammer Technology. The team has rich experience in the design, production, marketing and sales of electronic consumer goods.

It is worth mentioning that at about 16: 00 on November 1 this year, the State Tobacco Monopoly Bureau and the State Administration of Market Supervision issued the Notice on Further Protecting Minors from E-cigarettes.

The notice pointed out that in order to further strengthen the protection of minors’ physical and mental health and prevent minors from buying and smoking e-cigarettes through the Internet, from the date of issuance of this notice,urgeE-cigarette production and sales enterprises or individuals timely close the e-cigarette Internet sales website or client;urgeThe e-commerce platform closes the e-cigarette shop in time and removes the e-cigarette products in time;urgeEnterprises or individuals producing and selling electronic cigarettes withdraw electronic cigarette advertisements published through the Internet.

Just about 20 minutes before the official announcement of the above notice, Luo Yonghao, the founder of Hammer Technology, just forwarded the news that "vvild Xiao Ye disposable atomized electronic cigarette" will be officially launched in Tmall and JD.COM on November 11th.

It is understood that e-cigarette is a "re-entrepreneurship" project of Luo Yonghao after he left the Nut mobile phone team. Just when the outside world thought that he would stick to making mobile phones, Luo Yonghao stepped down as the legal representative and chairman of Beijing Hammer Digital Technology Co., Ltd. in December 2018 and turned to enter the e-cigarette industry.

Screenshot from Weibo, Luo Yonghao

This article is an exclusive manuscript of Observer. It cannot be reproduced without authorization.

Inventory of customs clearance mode of cross-border import e-commerce

Inventory of customs clearance mode of cross-border import e-commerce

At present, the customs clearance modes of cross-border e-commerce import business mainly include: express customs clearance, goods collection customs clearance and stock clearance.

What are the customs clearance modes for cross-border e-commerce?

(A) cross-border e-commerce import customs clearance mode-express customs clearance

After the order is confirmed, foreign suppliers will mail the goods directly from overseas to consumers through international express delivery. No customs documents.

Advantages: flexible, delivery only when there is business, no need to stock up in advance;

Disadvantages: When mixed with other express mail, the logistics clearance efficiency is low, and the cost will rise rapidly when the volume is large;

Suitable: the stage of less business volume and occasional sporadic orders.

(B) Cross-border e-commerce import customs clearance mode-goods collection customs clearance (orders first, then delivery)

Merchants package a number of sold goods in a unified way and transport them to domestic bonded warehouses through international logistics. E-commerce enterprises go through customs clearance procedures for each product. After being checked and released by the customs, e-commerce enterprises entrust domestic express delivery to consumers. Each order is accompanied by customs documents.

Advantages: flexibility, no need to prepare goods in advance, higher logistics clearance efficiency and lower overall logistics cost compared with express mail clearance.

Disadvantages: the packaging operation needs to be completed overseas, and the overseas operation cost is high, and the delivery from overseas takes a little longer.

Suitable for: at the stage of rapid growth of business volume, there are many orders every week. (3) Customs clearance mode of cross-border e-commerce import-stocking customs clearance (stocking first, then ordering)

Merchants stock overseas goods in batches to bonded warehouses under customs supervision. After consumers place orders, e-commerce enterprises go through customs clearance procedures for each product according to the orders, complete the veneer sheet and packaging in the bonded warehouses, and after being checked and released by the customs, e-commerce enterprises entrust domestic express delivery to consumers. Each order is accompanied by customs documents.

Advantages: bulk stocking to bonded warehouse in advance, the lowest international logistics cost, immediate delivery from bonded warehouse after orders are placed, the highest customs clearance efficiency, timely response to after-sales service requirements and the best user experience.

Disadvantages: the use of bonded warehouses has storage costs, and stocking will occupy funds.

Application: in the stage of large business scale and stable business volume. Purchase cost can be reduced by ordering in large quantities or in advance, and the international logistics cost can be reduced by gradually transitioning from air transportation to sea transportation, or the problem of capital occupation caused by stocking can be solved by pledge supervision financing.

(Source: Brother K chats with the sea)

I successfully developed my own technology to stop the plane from running off the runway and break the US monopoly.

Not long ago, Mr. Chen saw a novel thing on the Discovery Channel: Americans put a blocking bed at the end of some airport runways, which actually prevented planes from rushing off the runways. On the TV screen, the materials paved at the end of the runway successfully prevented a Boeing passenger plane from rushing out of the runway, which protected the plane and ensured the safety of passengers.

The technology presented in the picture is called Engineering Material Arresting System (EMAS), which has long been monopolized by foreign companies. On July 12th, 2012, EMAS, developed by China Civil Aviation Science and Technology Research Institute and with completely independent intellectual property rights, officially passed the qualification examination of Civil Aviation Administration of China and was approved for engineering application. This is an important progress made by China Civil Aviation in the research and development of major systems related to flight safety, and it is also the second EMAS in the world to be approved by government civil aviation authorities. The achievement of this achievement will greatly reduce the cost of installing the system in airports, thus promoting the effective improvement of safety and security capabilities of many plateau airports and airports with special terrain in China.

How to stop the plane from running off the runway?

With the rapid development of the world’s civil aviation industry, the number of take-off and landing flights has increased significantly, and the number of aircraft rushing off the runway has shown an upward trend. How to avoid serious accidents after the aircraft rushing off the runway has become an important issue for civil aviation safety. In order to solve this problem, as early as the 1960s, the British began to research and develop related technologies to stop planes that ran off the runway, but failed to form products for various reasons. By the 1980s, the Federal Aviation Administration (FAA) and an American company began to jointly develop the EMAS system.

In fact, EMAS is a kind of foam concrete with specific mechanical properties, which is laid on the ground of the runway extension line with a thickness of several tens of centimeters to form an arresting bed. Its width is consistent with the runway, and its length is between tens of meters and more than 100 meters. Once the plane rushes out of the runway, it enters it, and the foam concrete is crushed under the rolling of the wheels, so as to absorb the kinetic energy of the plane, and on the premise of ensuring the safety of the plane and the people on board, the plane will gradually slow down and finally stop in the arresting bed.

In 1990s, FAA approved the design method of EMAS system. In 1996, the first trial laying was carried out at Kennedy Airport in new york, and three planes were successfully stopped. Subsequently, the FAA issued a license for it and promoted it in civil airports in need in the United States. Up to now, 55 sets of EMAS systems have been laid in 35 civil airports in the United States, and 8 planes have been successfully stopped. At the same time, the United States promotes the EMAS system on a global scale. In recent years, the system has been installed at Jiuzhai Huanglong Airport in Sichuan and Songshan Airport in Taiwan.

Can solve the problem of running off the runway.

Sichuan Jiuzhai Huanglong Airport was built by cutting mountains, surrounded by mountains on three sides. Due to the influence of complex terrain and high altitude, pilots often feel that the runway is short during the flight mission of Jiuzhai Huanglong Airport, especially in rainy and snowy weather. Once the plane lands and stops taking off, there will be back spraying, brake failure or rushing off the runway, and the consequences will be unimaginable. Therefore, in 2006, when Jiuzhai Huanglong Airport carried out the second phase expansion project, two sets of EMAS systems were installed at the north and south ends of the runway respectively.

In China, a considerable number of airports are built by cutting mountains, commonly known as "desktop airports". Although these airports have established runway-end safety zones according to the standards, there are often steep slopes or cliffs outside the safety zones. Once the plane rushes out of the runway-end safety zone, the tragedy of plane crash and death will inevitably be staged. In addition, some airports in Linjiang, Linhai and residential areas also have such problems.

With the rapid development of civil aviation in China, the number of flights has increased dramatically. In order to maintain the past safety level, we need updated safety measures. According to the statistics of ICAO, the number of runway accidents in the world ranks first in the statistics of civil aircraft accident types. In recent years, the number of incidents of civil aviation rushing off the runway in China also ranks first in the statistics of serious accident symptoms of civil aircraft. It can be seen that the installation of EMAS system in the airport where the safety zone at the runway end is not long enough can solve the problem of the plane rushing off the runway and obviously improve the safe operation level.

Technical problems of

Before the EMAS developed by the China Academy of Civil Aviation Science and Technology was approved by the Civil Aviation Administration of China, there were no similar products in China. If we want to install it in our airports, we need to face three problems: high product price, long transportation distance and difficult system maintenance.

It is reported that in 2010, Taiwan Songshan Airport plans to lay a set of this system, with a budget as high as NT$ 430 million. Compared with 2006, when the system was laid at Jiuzhai Huanglong Airport in Sichuan, the price has increased significantly. Such a high cost, even if the government gives most subsidies, it is difficult for small and medium-sized airports in China that need to install EMAS system most.

China needs its own EMAS system! In 2010, under the direction of Li Jian, deputy director of the Civil Aviation Administration, the Academy of Aeronautics and Astronautics organized a research and development team headed by its main leaders and attended by dozens of scientific research backbones, and relevant units in the United Nations invested tens of millions of yuan. After more than two years, the technical problems of material production and system design methods have been overcome. In order to effectively verify the performance of the product and the safety of the system, the Institute of Aeronautics and Astronautics designed and built a special test bench, conducted dozens of tests on the process of wheel rolling materials, and obtained a lot of valuable data, and finally established a set of perfect simulation calculation model and design method for the blocking process. The Academy of Aeronautics and Astronautics also specially purchased a Boeing 737 aircraft from Air China. Since the fourth quarter of 2011, it has carried out six large-scale real aircraft verification tests using the second runway of Tianjin Airport. The test results show that the EMAS system developed by the Institute of Aeronautics and Astronautics has an effective blocking effect and can ensure the safety of the aircraft and the crew.

Development prospect of

"For China’s civil aviation, the EMAS project is a brand-new and groundbreaking project, and only the United States has mastered this technology in the world. We don’t have any experience to learn from. Doing this project well is of great significance for China civil aviation to export standards to the international civil aviation community, to enhance the international status of China civil aviation, to enhance the safety margin of complex airports, and to build a strong civil aviation country. " Li Jian, deputy director of CAAC, has repeatedly emphasized the importance of China Civil Aviation in developing its own EMAS system.

The responsible person of Academy of Aeronautics and Astronautics (Beijing) Science and Technology Development Co., Ltd. revealed to the reporter that the successful research and development of domestic EMAS system has greatly reduced the laying cost, and provided reasonable engineering solutions for many plateau airports, airports with complex terrain and other airports that are difficult to extend the runway safety zone for special reasons. It has a very broad market prospect. Tengchong Airport has decided to install EMAS system, and many airports at home and abroad have also shown strong interest in this product. "We have more than 10,000 square meters of production workshop in Tianjin Airport Economic Zone, which can meet the environmental requirements for the production and maintenance of blocking materials, and can ensure the stability of material performance, and can produce one set of materials required for EMAS system every month."

This year, ICAO will put forward the standard of increasing the length of the safety zone at the runway end in the "International Standards and Recommended Measures" to reduce the serious flight safety accidents caused by running off the runway. However, due to geographical or other environmental constraints, many airports are difficult to meet the new requirements for the length of runway safety zone. EMAS has been written into Article 3.5.5 of Airport Design and Operation, Volume I, Annex 14 of ICAO Convention on International Civil Aviation, which has become an internationally accepted equivalent safety measure.

It is understood that although the price of domestic EMAS system has dropped significantly compared with similar products abroad, it is also a huge expense for many airports, especially small and medium-sized airports. In view of the purpose of laying EMAS system to improve the safety of airport operation, CAAC is working on formulating relevant subsidy policies to support the popularization and application of EMAS system.

Here comes Gemini, Google’s strongest model! Really multi-modal, pouring all resources and supporting Chinese, GPT4 is no longer unique.

Google’s strongest AI model, which has attracted much attention and is considered by the industry to be the most likely to beat GPT-4, has finally appeared!

On December 6th, US Western Time, Google CEO Sundar Pichai and DeepMind Director Demis Hassabis jointly announced the official launch of Gemini 1.0 in official website.

Gemini is jointly created by several Alphabet teams such as Google Research and DeepMind. As a new powerful multi-modal artificial intelligence model, it can induce, understand, operate and combine different types of information. It can not only process text, images, video and audio, but also complete complex tasks in mathematics, physics and other scientific fields, and can understand and generate high-quality codes in various programming languages.

Pichai described Gemini as "our largest and most powerful AI model to date" and said that it has shown the most advanced performance in many leading benchmarks. "The first generation of Gemini 1.0 was optimized for different sizes, namely: Ultra, Pro and Nano. These are the first models to enter the Gemini era and the first realization of our vision when we established Google DeepMind earlier this year. "

At the Google I/O conference in May this year, Pichai spoiled the news that Google was developing Gemini. It is described as the "Next Generation Multi-modal Intelligent Network", which is designed for API integration. It is said that it has trillions of parameters like GPT-4, but its computing power is five times that of GPT-4, and it can perform more complex and diverse tasks.

To this end, Google also merged its two strongest artificial intelligence laboratories: Google Brain and DeepMind, led by Demis Hassabis, the former CEO of DeepMind, and invested hundreds of millions of dollars in research and development of Gemini.

Even sergey brin, the co-founder of Google, who has resigned for four years, has returned to the office of Mountain View in Silicon Valley to participate in the Gemini decision-making and join the LLM scuffle.

But just last week, The Information quoted people familiar with the matter as saying that Pichai recently silently canceled a series of Gemini public appearances that should have been held in California, new york and Washington, D.C., because it was found to be "unreliable in handling some non-English queries", which cast a gray color on the product launch process.

Perhaps to consolidate market confidence, early this morning, Gemini 1.0 suddenly made its grand debut, appearing in the public’s field of vision and quickly occupying the front pages of major scientific and technological media.

So, what is the strongest artificial intelligence model that Google is betting on the whole army?

Hassabis, head of DeepMind, called Gemini their most flexible model, which can run efficiently on all kinds of devices from data centers to mobile devices.

In order to achieve this extensibility, Gemini 1.0 has designed three versions with different functions and sizes:

Gemini Nano —The most efficient model on the end-side equipment. Designed for smart phones, it can perform efficient AI processing tasks without connecting to an external server. Now it has been integrated into Pixel 8 Pro, which can support the function of "summarizing text" in recording applications and the function of "intelligent reply" in Gboard. Starting with WhatsApp, it will be extended to more applications next year.

Gemini Pro —The best model for various tasks running in Google data center. Support the latest version of the AI chat robot Bard from today. It can respond quickly and understand complex queries, which is the biggest upgrade since Bard was introduced. At present, it provides English services to more than 170 countries and regions, and plans to support new languages and regions in the coming months, and apply them to more Google products such as search, advertising, Chrome and Duet AI.

Gemini Ultra -The largest and most powerful model, dedicated to highly complex tasks, will be provided to developers and enterprise customers early next year after completing the current testing phase. At that time, an updated version of Bard Advanced based on Gemini Ultra will be launched.

In terms of model architecture, Gemini still uses Transformer architecture, adopts an efficient attention mechanism, and supports the context length of 32k.

Google confidently said that after rigorous testing and performance evaluation of the Gemini model, from natural image, audio and video understanding to mathematical reasoning,Among the 32 academic benchmarks widely used in the research and development of large-scale language models, the performance of Gemini Ultra has exceeded the most advanced level represented by ChatGPT at present.. Before the release of Gemini, Google conducted a series of tests to evaluate it with standard industry indicators.

In the MMLU test, the score rate of Gemini Ultra is 90.0%, which is higher than that of GPT-4 (86.4%), making it the first model to surpass the performance of human experts. The MMLU test covers 57 subjects, including mathematics, physics, history, law, medicine and ethics, and aims to evaluate the model’s understanding and problem-solving ability in the global knowledge field.

In Reasoning, Math and Code, except HellaSwag, which lags behind GPT-4 by 87.8%, others include challenging math problems such as multi-step reasoning, algebra/geometry/pre-calculus and so on.

In terms of multimodal capability, Gemini Ultra achieved a SOTA score of 59.4% in the new MMMU benchmark test, which exceeded the 56.8% of the multimodal version GPT-4V of OpenAI. This benchmark test spans many different fields and requires precise reasoning for many tasks.

In the image benchmark test, even without the assistance of Object Character Recognition (OCR) system, the performance of Gemini Ultra is better than all previous models only by analyzing pixel information. In audio testing, the scores of automatic speech recognition and automatic speech translation of Gemini are higher than those of Whisper system connected to GPT-4.

Hassabis said that this highlights the superiority of Gemini’s native multimodal. Up to now, the usual way to create multi-modal models is to train individual components of different modes independently, and then splice them together to try to simulate some functions.

Although such models can sometimes effectively perform specific tasks such as describing pictures, they often perform poorly in more conceptual and complex reasoning.

Gemini was originally designed in a native multi-modal way, and was pre-trained in different modes from the beginning using TPUs v4 and v5e chips designed by Google.. Then it is fine-tuned with more additional multimodal data to improve its performance.

This method enables Gemini to understand and reason all kinds of input content more naturally in the initial stage, and its ability in almost all fields has reached an unprecedented advanced level.

First of all, Gemini has complex multi-modal reasoning ability, which can help to understand complex written and visual information and discover indistinguishable knowledge content in massive data.

For example, it is instructed to filter irrelevant papers through the natural language prompt, or extract key data through reading. With a lunch break, Gemini can help you extract 250 document points from 200,000 papers, and further transform the data into any required chart form. This will greatly help to achieve innovative breakthroughs in science, finance and other fields at a digital speed.

The trained Gemini can obviously recognize and understand text, image and audio data at the same time, better understand subtle information and answer questions related to complex topics. This makes it especially good at explaining reasoning in subjects such as mathematics and physics. In the example, the staff showed that Gemini can check handwriting physical mistakes and explain the correct way.

In order to show the multimodal capabilities of Gemini more intuitively, Brother Chai released a video in X, saying that "the best way to understand the amazing potential capabilities of Gemini is to look at their practical applications".

In the video, Gemini taught the staff the pronunciation of "duck" in Mandarin according to the instructions, and also explained the Chinese tone.

The staff also gave Gemini a demonstration of interaction only in Chinese. By asking about the indoor light in a picture, Gemini is asked to give the orientation of the apartment in use. Gemini answers in Chinese and guesses that the room faces south. Circle a plant in the photo and ask what kind of lighting it needs. gemini then explains the plant species and lighting requirements. The whole process is as smooth as the mother tongue, which shows that Gemini is outstanding in multilingual environment, which is no less than GPT-4.

In addition, Gemini can understand, interpret and generate high-quality codes of the most popular programming languages in the world, such as Python, Java, C++ and Go. The ability to achieve cross-language work and handle complex information makes it one of the world’s leading basic coding models, helping programmers to use the powerful AI model as a collaborative tool to design applications.

For developers, starting from December 13th, Gemini Pro can be obtained through the Gemini API in Google AI Studio or Google Cloud Vertex AI. Android developers can also use Gemini Nano, the most efficient model for end-to-end tasks, through AICore.

Looking back on the development of Google’s big model all the way, compared with the continuous and rapid update of OpenAI’s "Wang Fried", Microsoft always seems to be one step behind when it integrates various AI functions of GPT into core products and pushes them to customers. When Bard, a chat robot, was released in February this year, it got off to a bad start, and the market value evaporated by 100 billion dollars overnight with a factual error. Benchmarking Microsoft Copilot’s Duet AI work suite, the market response was moderate, and the financial performance of cloud services also lost to Microsoft.

Especially after the internal friction caused by the reorganization of Brain and DeepMind teams and the loss of senior talents to OpenAI, Google’s AI battle is even more exhausted.

However, this is, after all, an AI pioneer who contributed to Transformer’s pioneering masterpiece Attention is all you need and the landmark artificial intelligence program AlphaGo, and inspired the subsequent development of many large models including ChatGPT. No matter from the technical genes, training data, capital and infrastructure, it should have one of the best strengths.

The release of Gemini is regarded by Google as the most critical technological innovation in the past decade. Can it make Google rally, beat OpenAI and regain the throne of the big model stadium?

Will the AI competition pattern be reshaped after Genmini Ultra comes out next year?

And, has everyone tried the new Google Bard? How do you feel?

Welcome to leave a message to share, or join the group to discuss with us!

Guide: western medicine treatment of herpes zoster

Click on "Huanghuai nurse" above to follow.

guide language

The treatment scheme of herpes zoster can be roughly divided into traditional Chinese medicine therapy and western medicine therapy. Today, we will learn the western medicine therapy recommended by the guide.

Therapeutic goal of herpes zoster

Relieve acute pain; Shorten the duration of skin lesions; Prevent the spread of skin lesions; Prevent or reduce complications.

First, antiviral drugs

Commonly used drugs in clinical treatment of herpes zoster can effectively shorten the course of disease, accelerate the healing of rash, reduce the formation of new rash and reduce the spread of virus to internal organs. It should be used within 72 hours after the eruption, so as to quickly reach and maintain the effective concentration and obtain the best therapeutic effect. At present, the approved systemic antiviral drugs include acyclovir, valaciclovir, famciclovir, bromovudine and foscarnet sodium.

acyclovir

Function characteristics:

Acyclovir triphosphate is produced by phosphorylation of viral thymidine kinase in infected cells, which can inhibit viral DNA polymerase and stop the extension of viral DNA chain.

  Usage:

(1) Oral administration: 400-800 mg/time, 5 times/day, for 7 days;

(2) Intravenous drip: 5 ~ 10 mg/kg for patients with immune impairment or serious nervous system diseases, once every 8 hours, with a course of 7 days. 

Precautions:

Patients should drink plenty of water during the administration of acyclovir to prevent acyclovir from precipitating in renal tubules and damaging renal function.

Valaciclovir

Function characteristics:

The prodrug of acyclovir is quickly absorbed by oral administration and quickly converted into acyclovir in gastrointestinal tract and liver, and its bioavailability is 3~5 times that of acyclovir.

  Usage:

Oral administration: 300 ~ 1000 mg/time, 3 times/day, for 7 days.

Fanciclovir

Function characteristics:

The prodrug of penciclovir is rapidly converted into penciclovir after oral administration, and maintains a long half-life in cells. The mechanism of action is the same as that of acyclovir, the bioavailability is higher than that of acyclovir, and the frequency and dosage of administration are lower than that of acyclovir.

  Usage:

Oral administration: 250 ~ 500mg/time, 3 times/day, for 7 days.

brivudine tablets

Function characteristics:

The antiviral effect is highly selective, and the process of inhibiting virus replication is only carried out in virus-infected cells. 

Usage:

Oral administration: 125mg//day, l times/day, for 7 days.

Sodium foscarnet

Function characteristics:

Blocking the phosphate binding site of viral DNA polymerase in a non-competitive way, thus showing antiviral activity.

  Usage:

Intravenous drip: 40 mg/kg each time, once every 8 hours.

Note meaning 

Patients with renal insufficiency should reduce the dosage accordingly;

If renal function continues to decline, acyclovir should be stopped immediately and famciclovir or other antiviral drugs should be used to continue treatment;

For patients suspected of renal insufficiency, creatinine level should be detected before initial administration (creatinine level is not required for bromovudine).

Second, analgesics

Mild to moderate pain:Acetaminophen and tramadol can be selected; 

Moderate and severe pain:

1. Opioid drugs, such as morphine or oxycodone;

2. Drugs for the treatment of neuropathic pain, such as calcium channel regulator gabapentin and pregabalin, in addition to amitriptyline and 5% lidocaine patch. Severe acute pain during herpes zoster is a risk factor for post-herpetic neuralgia (PHN). Combined with calcium channel regulator can not only effectively relieve pain, but also reduce the occurrence of PHN. Studies have shown that early use of pregabalin can significantly reduce the pain score of herpes zoster, especially within 7 days of herpes occurrence, which can significantly reduce the incidence of PHN. The pain of elderly patients with herpes zoster is more common and severe, which seriously affects all aspects of life, such as anxiety, disorder and inability to work or live normally. Studies have shown that pregabalin combined with oxycodone can not only further reduce the incidence of PHN, but also improve the daily activities and sleep of patients and improve their quality of life.

Third, glucocorticoid

At present, there is still controversy about whether to use glucocorticoid to treat herpes zoster.

It is generally believed that systematic application of glucocorticoid in the early stage of acute onset of herpes zoster and gradual decrease can inhibit the inflammatory process, shorten the duration of acute pain and the healing time of skin lesions, but it is ineffective for the pain with PHN. 

Recommended dose:The initial dosage of prednisone is 30~40 mg//day, which is taken orally and gradually reduced, and the course of treatment is 1~2 weeks.

 Fourth, neurotrophic drugs

It is also helpful to relieve neuroinflammation and neuralgia. Commonly used drugs include mecobalamin, vitamin B1 and vitamin B12, etc., which are taken orally or injected intramuscularly.

Five, topical drugs

Mainly dry and anti-inflammatory. 

Blister fluid is not broken:Calamine lotion, acyclovir cream or penciclovir cream can be used externally. 

After herpes is broken:

3% boric acid solution wet compress;

1: 5000 furacilin solution wet compress;

0.5% neomycin ointment for external use;

2% mupirocin ointment. 

Ophthalmic herpes:3% Acyclovir Eye Ointment and Iodine Eye Drops for External Use.

References: [1] Herpes Zoster Expert Consensus Working Group. Herpes Zoster Expert Consensus in China [J]. Chinese Journal of Dermatology .2018,51 (6): 403-406.

Laiyuan/Yunque

Dozens of dead birds fell from the sky! A rare scene on the streets of Russian cities leads netizens to speculate.

  Russian video screenshot today

  Overseas Network September 22ndAccording to the news of "Russia Today" on the 21st, some pictures and videos have been circulated on Russian social media platforms recently: a street in Barakovo is full of dead birds. This rare scene triggered a series of brain hole conjectures by netizens.

  According to reports, this incident occurred in Barakovo, Saratov State, southwestern Russia, which is famous for its large nuclear power plant. According to videos and pictures uploaded by Russian social media users, local residents witnessed the bodies of dozens of dead birds scattered on a road.

1600758482562342.png

  Source: Russia today

  Below the video, Russian netizens gave many conjectures about why dead birds fell from the sky. Some people blame it on natural phenomena, such as a strong wind or an accidental collision between two birds. Others think that fireworks and exhaust gas from factories may cause a large number of deaths, and some even say that it is related to 5G equipment, although this technology has not yet entered Russia.

  "At the beginning of the nuclear disaster TV series Chernobyl, all the birds died." A comment with the highest praise linked the incident to the American HBO hit drama. The animal medical department of Saratov State is currently investigating this incident, which some people think may be related to bird flu. (Overseas Network Zhang Qi)

China’s first intelligent blind road application scenario started.

A few days ago, more than 40 people with severe visual impairment came to Hezhuang Cultural and Sports Center in Qiantang District, incarnating as "raiders of the lost ark", and launched an interesting "treasure hunt" in the first application scene of wisdom blind road in China.

At the scene, after the simple training of the staff of the R&D unit, the participants easily mastered the use of the wisdom cane. At the beginning of the activity, each participant got the wisdom cane distributed by the staff. After quickly connecting to the related small programs on their mobile phones, they turned into "raiders of the lost ark" on the designated route.

The treasure hunt route is nearly 100 meters long. Participants will pass through barrier-free ramps, barrier-free elevators and barrier-free doors, and go upstairs, go straight and turn under the guidance of the wisdom blind road. After reaching the finish line, participants can receive corresponding rewards by virtue of the "treasure list" on their mobile phones.

After the experience, visually impaired people praised the innovation of electronic blind roads-

"Enter the end point accurately on the mobile phone and follow the guide. There are voice prompts all the way, which is very clear. When I was looking for treasure, I was particularly happy when I heard the gold coin ringing. " Participant Shen Haidan said.

"Electronic blind roads are more accurate, more secure, more convenient and more humanized than traditional blind roads. The prompts of’ Go Forward’,’ Turn Left’ and’ Turn Right’ make us feel that the service is warm and caring. At present, I feel that there is a slight delay in matching, and I hope I can continue to improve. " Participant Zheng Yan said.

"Electronic blind roads can be located in bathrooms, conference rooms, offices and other places in buildings, which is more suitable for blind friends to travel, and I hope it can be promoted!" Participant Jiang Longxiang said.

The first "Treasure Hunt" of the "Qiantang Cup" was directed by Hangzhou Blind Association, and jointly sponsored by Qiantang Disabled Persons’ Federation and Hezhuang Sub-district Office.

In recent years, Hangzhou Disabled Persons’ Federation and Qiantang Disabled Persons’ Federation have devoted themselves to building the Hezhuang Cultural and Sports Center in Qiantang District as a model of the national advanced barrier-free cultural and sports center. After successfully building the first barrier-free swimming pool in China, they also focused on information barrier-free construction, and created the first intelligent blind road application scene in China.

Zhao Cheng, chairman of Hangzhou Blind Association, introduced that the application scene of the intelligent blind road compensates for the lack of vision through sound, and stimulates the enthusiasm of visually impaired people through technology, which can help them better participate in the experience and integrate into society. "I hope that with the joint efforts of all walks of life in the future, severely visually impaired people can also go out of their homes more conveniently, set foot on urban blind roads, enjoy urban public transportation and enjoy work and life without obstacles."

Alipay responded to promote the optimization of payment service: the amount has been raised, and multi-language and one-code communication will be launched in the near future.

On March 7th, the General Office of the State Council issued the Opinions on Further Optimizing Payment Services and Improving Payment Convenience, which mentioned that the needs of the elderly, foreigners coming to China and other groups should be fully considered, and the aging and internationalization service arrangements should be made.

The relevant person in charge of the People’s Bank of China said that the Opinions put forward six major tasks:

First, effectively improve the acceptance environment of bank cards to meet the needs of the elderly, foreign visitors to China and other groups of "food, housing, transportation, travel, shopping, entertainment, medical care" and other scenarios.

Second, adhere to the positioning of cash, continuously optimize the cash use environment, and continuously improve the level of foreign currency exchange and cash services.

The third is to further enhance the convenience of mobile payment, encourage banks, payment institutions and clearing institutions to cooperate, and make good service arrangements such as aging and internationalization.

The fourth is to better protect consumers’ right to pay. Large business districts, tourist attractions, entertainment venues, hotel accommodation and other key places above designated size must support diversified payment methods such as mobile payment, bank cards and cash.

Fifth, optimize the account opening service process, rationally implement the classified and hierarchical management of accounts, keep a close eye on key areas, key outlets and key business links, improve supporting measures for account opening, and continuously improve the service level of accounts.

Sixth, comprehensively use various ways and channels to continuously strengthen the promotion of payment services.

On the evening of March 7th, Alipay said that it was actively responding to the relevant decision-making arrangements of the CPC Central Committee and the State Council, and with the support and guidance of the People’s Bank of China and the Foreign Exchange Bureau, it was solidly promoting the implementation of various measures to continuously optimize the payment services for the elderly and foreigners coming to China. It is reported that Alipay has completed the promotion and optimization of the transaction limit for foreigners, with the single transaction limit raised from $1,000 to $5,000 and the annual transaction limit raised from $10,000 to $50,000. In addition, new services such as multi-language translation and overseas wallet ride code "One Code Pass" will be launched one after another.

Tenpay said that with the support and guidance of the People’s Bank of China and the foreign exchange bureau, Tenpay has implemented a number of measures around "aging and upgrading". In terms of facilitating the payment of foreign nationals in China, simplification measures have continued to land. Since the comprehensive upgrade in July last year, the transaction volume of WeChat payment foreign cards has continued to grow. Compared with the opening of only some pilot merchants, the highest number of transactions in a single day in February 2024 increased nearly five times.

7 categories of mainstream 3D printing technologies, all of which can be understood.

Many people think that 3D printing is to extrude materials from hot nozzles and stack them into shapes, but in fact 3D printing is far more than that! Today, Antarctic Bear will introduce seven kinds of 3D printing processes. Even 3D printing can clearly distinguish different 3D printing processes.

In fact, 3D printing, also known as additive manufacturing, is a general term, covering several completely different 3D printing processes. These technologies are worlds apart, but the key process is the same. For example, all 3D printing starts with a digital model, because the technology is digital in nature. Parts or products are originally electronic files designed by computer aided design (CAD) software or obtained from digital parts library. Then the design file is decomposed into slices or layers by special construction preparation software for 3D printing, and the path instructions to be followed by the 3D printer are generated. Next, you will understand the differences between these technologies and the typical uses of each technology.

Why are there seven types?

The types of additive manufacturing can be classified according to the products they produce or the types of materials they use, and the International Organization for Standards (ISO) divides them into seven general types (but these seven 3D printing categories can hardly cover more and more technical sub-types and mixed technologies). :

● Material extrusion

● Reduction polymerization

● Powder bed fusion

● Material spraying

● Adhesive spraying

● Directed energy deposition

● Sheet lamination

First, material extrusion

△ Material extrusion 3D printing

Material extrusion as the name implies: material is extruded through a nozzle. Usually, this material is a plastic filament, which is melted and extruded through a heated nozzle. The printer places materials on the building platform along the process path obtained by software. The filament then cools and solidifies to form a solid object. This is the most common form of 3D printing. At first glance, it sounds simple, but considering the extruded materials, including plastics, metals, concrete, bio-gel and various foods, it is actually a very broad category. The price of this type of 3D printer ranges from $100 to seven figures.

● Subtypes of material extrusion: fused deposition modeling (FDM), building 3D printing, micro 3D printing and biological 3D printing.

● Materials: plastic, metal, food, concrete, etc.

● Dimensional accuracy: 0.5% (lower limit: ±0.5mm)

● Common applications: prototype, electrical enclosure, shape and fit test, fixture and fixture, investment casting model, house, etc.

● Advantages: 3D printing method with the lowest cost and wide range of materials.

● Disadvantages: Generally, the material performance is low (strength, durability, etc.), and the dimensional accuracy is usually not high.

1. Fused Deposition Molding (FDM)

△FDM parts can be made of metal or plastic on various 3D printers.

FDM 3D printer is a multi-billion dollar market with thousands of machines, ranging from basic models to complex models of manufacturers. The FDM machine is called Fuse Manufacturing (FFF), which is exactly the same technology. Like all 3D printing technologies, FDM starts with a digital model and then converts it into a path that a 3D printer can follow. Using FDM, one filament (or several filaments at a time) on the bobbin is loaded into a 3D printer and then sent to the printer nozzle in the extrusion head. The nozzle or nozzles of the printer are heated to the required temperature to soften the filament, thus connecting successive layers to form a solid part.

When the printer moves the extrusion head along the specified coordinates on the XY plane, it will continue to lay the first layer. Then the extrusion head rises to the next height (Z plane), and the process of printing the cross section is repeated, building layer by layer until the object is fully formed. Depending on the geometry of the object, it is sometimes necessary to add a support structure to support the model when printing, for example, if the model has a steep overhang. These supports are removed after printing. Some supporting structure materials can be dissolved in water or another solution.

△FDM 3D printers provide a wide range of machines for amateurs, small businesses and manufacturers (sources: Creality, Raise3D, Stratasys).

2.3D biological printing

△3D bio-printing is similar to traditional 3D printing, but the raw materials are quite different.

3D biological printing or biological 3D printing is an additive manufacturing process in which organic or biological materials (such as living cells and nutrients) are combined to create a natural three-dimensional structure similar to tissues. In other words, bioprinting is a kind of 3D printing, which can produce anything from bone tissues and blood vessels to living tissues. It is used in various medical research and applications, including tissue engineering, drug testing and development, and innovative regenerative medicine therapy. The actual definition of 3D bioprinting is still developing. Essentially, the working principle of 3D bio-printing is similar to FDM 3D printing, and it belongs to the material extrusion series. (Although extrusion is not the only bio-printing method)

3D bio-printing uses the material (bio-ink) discharged from the needle to create a printed layer. These materials, called bio-inks, are mainly composed of living substances, such as cells in carrier materials, such as collagen, gelatin, hyaluronic acid, silk, alginate or nano-cellulose, which serve as molecular scaffolds for structural growth and nutrients.

3. Building 3D printing

△ Building 3D printing

Building 3D printing is a rapidly developing field of material extrusion. This technology involves the use of super-large 3D printers (usually up to tens of meters) to extrude building materials such as concrete from nozzles. These machines usually appear in the form of gantry or robotic arm systems. 3D architectural printing technology is now used in residential buildings, architectural features and construction projects from wells to walls. Some researchers say that it may significantly change the whole construction industry, because it reduces the demand for labor and construction waste.

There are dozens of 3D printed houses in the United States and Europe, and 3D building technology is being researched and developed, which will use materials found on the moon and Mars to build habitats for future expeditions. Printing with local soil instead of concrete as a more sustainable building method has also attracted attention.

Second, reduction polymerization

△ Reduction polymerization using laser

Barrel polymerization (also known as resin 3D printing) is a series of 3D printing processes, which uses a light source to selectively cure (or harden) photopolymer resin in a barrel. In other words, light is precisely directed at a specific point or area of liquid plastic to harden it. After the first layer is cured, the building platform will move up or down (depending on the printer) by a small amount (usually between 0.01 and 0.05 mm), and the next layer will be cured and connected with the previous layer. This process is repeated layer by layer until a 3D part is formed. After the 3D printing process is completed, the object is cleaned to remove the remaining liquid resin and post-cured (in the sun or ultraviolet room) to enhance the mechanical properties of the parts.

The three most common forms of barrel polymerization are stereolithography (SLA), digital light processing (DLP) and liquid crystal display (LCD), also known as mask stereolithography (MSLA). The fundamental difference between these types of 3D printing technologies lies in the light source and the way it is used to cure the resin.

△ vats polymerization uses light to harden photosensitive resin layer by layer.

Some 3D printer manufacturers, especially those that manufacture professional 3D printers, have developed unique and patented photopolymerization variants, so you may see different technical names in the market. Carbon, an industrial 3D printer manufacturer, uses a barrel polymerization technology called Digital Photosynthesis (DLS), Origin of Stratasys calls it Programmable Photopolymerization (P3), Formlabs provides a technology called Low-Force Stereolithography (LFS), and Azul 3D is the first to commercialize the barrel polymerization in the form of large-area rapid printing (HARP). There are also photolithography-based metal manufacturing (LMM), projection micro-stereolithography (PμSL) and digital composite manufacturing (DCM), which is a technology of filling photopolymer and can introduce functional additives (such as metal and ceramic fibers) into liquid resin.

● Types of 3D printing technology: Stereolithography (SLA), Liquid Crystal Display (LCD), Digital Light Processing (DLP), Micro Stereolithography (μSLA), etc.

● Material: photopolymer resin (castable, transparent, industrial, biocompatible, etc.)

● Dimensional accuracy: 0.5% (the lower limit is 0.15mm or 5nm, using μSLA).

● Common applications: injection molding polymer prototypes and end-use parts, jewelry casting, dental applications, consumer goods.

● Advantages: smooth surface finish and fine feature details.

1. Stereolithography (SLA)

△ Stereolithography (SLA) Examples of SLA 3D printing from 3D Systems, DWS and Formlabs.

SLA is the first 3D printing technology in the world. Stereolithography was invented by Chuck Hull in 1986. He applied for a patent for this technology and set up 3D Systems Company to commercialize it. Today, this technology can be used by enthusiasts and professionals from many 3D printer manufacturers. SLA uses laser beam to aim at a barrel of resin, selectively solidifies the cross section of the object in the printing area, and builds it layer by layer. When most SLA printers use solid-state lasers to cure components. One disadvantage of this barrel polymerization is that compared with our next method (DLP), the point laser may take longer to track the cross section of the object, and the latter will flash light to immediately harden the whole layer. However, laser can produce stronger light, which is required by some engineering-grade resins.

△SLA 3D printer uses one or more lasers to track and cure a single layer of resin at one time.

Micro-stereolithography (μSLA)

Micro-stereolithography technology can print micro-parts, and the resolution is between 2 microns (μm) and 50 microns. For reference, the average width of human hair is 75 microns. It is one of the "micro 3D printing" technologies. μSLA involves exposing photosensitive material (liquid resin) to ultraviolet laser. The difference lies in the special resin, the complexity of laser and the addition of lens, which will produce almost incredible small light spots.

△Nanoscribe and Microlight3D are two leading manufacturers of TPP 3D printers (source: Nanoscribe and Microlight3D).

Two-photon polymerization (TPP)

Another micro 3D printing technology, TPP (also called 2PP), can be classified as SLA, because it also uses laser and photosensitive resin, and it can print parts smaller than μSLA, as small as 0.1 micron. TPP uses pulsed femtosecond laser to focus on a narrow spot in a large barrel of special resin. This point is then used to cure a single 3D pixel, also called a voxel, in the resin. By curing these nano-scale to micron-scale voxels layer by layer in a predefined path. TPP is currently used in research, medical applications and the manufacture of micro parts, such as microelectrodes and optical sensors.

△ Micro 3D printing: TPP technology

2. Digital Light Processing (DLP)

△ DLP 3D printing parts of △Anycubic, Carbon and ETEC

DLP 3D printing uses a digital light projector (instead of a laser) to flash a single image of each layer on a layer or resin at the same time (or to expose a larger part for multiple times). DLP (more common than SLA) is used to produce larger parts or larger parts in a single batch, because no matter how many parts are in construction, each layer needs exactly the same exposure time, which is more efficient than the point laser method in SLA. The image of each layer consists of square pixels, resulting in a layer formed by small rectangular blocks called voxels. Light is projected onto the resin using a light emitting diode (LED) screen or a UV light source (lamp) and onto the construction surface through a digital micromirror device (DMD).

△ Digital Light Processing (DLP) resin 3D printer has a hobby version and a complete manufacturing machine.

Modern DLP projectors usually have thousands of micron-sized LEDs as light sources. Their on-off states are independently controlled, which can improve the XY resolution. Not all DLP 3D printers are the same. The power of light source, the lens it passes through, the quality of DMD and many other parts that make up a machine worth 300 dollars are quite different compared with a machine worth more than 200,000 dollars.

Top-down DLP

The light source of some DLP 3D printers is installed on the top of the printer, and shines down on the resin barrel instead of up. These "top-down" machines flash one layer of images from the top, curing one layer at a time, and then put the cured layer back in the vat. Every time the building board is lowered, the recoating machine installed at the top of the vat will move back and forth on the resin to level the new layer. According to the manufacturer, because the printing process will not resist gravity, this method can produce more stable parts output for larger prints. There is a limit to how much weight can be hung vertically from the building board when printing from bottom to top. The resin barrel also supports printed parts during printing, which reduces the need for supporting structures.

△BMF’s MicroArch S230 can print detailed parts of polymers or ceramics as small as 2 microns (source: BMF).

Projection microlithography (PμSL)

As a unique type of barrel aggregation itself, PμSL is classified as a subcategory of DLP. This is another micro 3D printing technology. PμSL uses ultraviolet rays from the projector to cure the specially formulated resin layer in micron scale (2 micron resolution and as low as 5 micron height). This additive manufacturing technology is developing continuously because of its low cost, accuracy, speed and the range of materials (including polymers, biomaterials and ceramics). It has shown the application potential from microfluidic and tissue engineering to micro-optics and biomedical micro-devices.

Metal Manufacturing Based on Lithography (LMM)

This is another "distant relative" of DLP. This method of 3D printing using light and resin can create tiny metal parts for applications such as surgical tools and micromechanical parts. In LMM, metal powder is uniformly dispersed in photosensitive resin, and then selectively polymerized by blue light exposure through a projector. After printing, the polymer components of the blank parts are removed, leaving all-metal degreased parts, which are completed in the sintering process in the furnace. Raw materials include stainless steel, titanium, tungsten, brass, copper, silver and gold.

△ Micro-metal 3d printing parts made on Incus 3D printing with LMM technology.

3. Liquid crystal display (LCD)

△ LCD 3D printing components from Elegoo, Photocentric and Nexa3D.

Liquid crystal display (LCD), also known as mask stereolithography (MSLA), is very similar to the above DLP, except that it uses LCD screen instead of digital micromirror device (DMD), which has a significant impact on the price of 3D printer. Like DLP, LCD photomask is digitally displayed and consists of square pixels. The pixel size of LCD photomask determines the granularity of printing. Therefore, the XY accuracy is fixed and does not depend on the zoom or zoom degree of the lens, just like DLP. Another difference between DLP printers and LCD technology is that the latter uses an array of hundreds of individual emitters instead of a single point emitting light source like a laser diode or DLP bulb.

△ Today, LCD resin 3D printing technology is shifting from consumer machines to industrial machines.

Similar to DLP, LCD can achieve faster printing time than SLA under some conditions. This is because the whole layer is exposed at one time instead of tracking the cross-sectional area with a laser spot. Due to the low cost of LCD unit, this technology has become the first choice in the field of low-cost desktop resin printers, but this does not mean that it has not been used professionally. Some industrial 3D printer manufacturers are breaking through the technical limits and achieving remarkable results.

Third, powder bed fusion

△ Powder bed fusion

Powder bed fusion (PBF) is a 3D printing process, in which a thermal energy source selectively melts powder particles (plastic, metal or ceramic) in a construction area to create solid objects layer by layer. Powder bed fusion 3D printer spreads a thin layer of powder material on the printing bed, usually using a blade, roller or wiper. The energy from the laser fuses a specific point on the powder layer, and then another powder layer is deposited and fused to the previous layer. This process is repeated until the whole object is manufactured, and the final product is wrapped and supported by unmelted powder.

△ Metal laser powder bed fusion process

PBF can manufacture parts with high mechanical properties (including strength, wear resistance and durability) for the end use of consumer goods, machinery and tools. 3D printers in this market segment are getting cheaper and cheaper (starting at around $25,000), but it is considered as an industrial technology.

● Types of 3D printing technology: selective laser sintering (SLS), laser powder bed melting (LPBF) and electron beam melting (EBM).

● Materials: plastic powder, metal powder and ceramic powder.

● Dimensional accuracy: 0.3% (lower limit: ±0.3mm)

● Common applications: production of functional parts, complex pipes (hollow design) and small batch parts.

● Advantages: functional components, excellent mechanical properties, complex geometry.

● Disadvantages: The cost of the machine is high, usually high-cost materials, and the construction speed is slow.

1. Selective laser sintering (SLS)

△ SLS 3D printing parts of △Sinterit

Selective laser sintering (SLS) uses lasers to make objects from plastic powder. First, a box of polymer powder is heated to a temperature just below the melting point of the polymer. A very thin layer of powder material (usually 0.1 mm thick) is then deposited on the building platform using a recoating blade or wiper. The laser begins to scan the surface according to the pattern arranged in the digital model. The laser selectively sintered the powder and solidified the cross section of the object. When scanning the whole cross section, the building platform moves down one layer in height. The recoating blade deposits a new layer of powder on the recently scanned layer, and the laser sinter the next cross section of the object onto the previously solidified cross section.

△ SLS 3D printing parts can be dusted and cleaned manually or automatically.

Repeat these steps until all objects are made. The unsintered powder remains in place to support the object, which reduces or eliminates the need for supporting structures. After the parts are taken out of the powder bed and cleaned, there is no need for other necessary post-treatment steps. Parts can be polished, coated or colored. There are many differentiation factors between SL3D printers, including not only their size, but also the power and quantity of laser, the spot size of laser, the time and mode of heating bed and the distribution mode of powder. The most common materials in SL3D printing are nylon (PA6, PA12), but flexible parts can also be printed with TPU and other materials.

△SLS 3D printer uses polymer powder and laser to form solid parts.

2. Micro-selective laser sintering (μSLS)

μSLS belongs to SLS or laser powder bed fusion (LPBF) described below. It uses laser to sinter powdery materials, such as SLS, but this material is usually metal rather than plastic, so it is more like LPBF. It is another micro 3D printing technology, which can create parts with micro (less than 5 μm) resolution.

△ Metal 3D MicroPrinting from 3D microprint

In μSLS, a layer of metal nanoparticle ink is coated on the substrate and then dried to produce a uniform nanoparticle layer. Next, the laser patterned with the digital micromirror array is used to heat the nanoparticles and sinter them into a desired pattern. This set of steps is then repeated to build each layer of the 3D component in the μSLS system.

3. Laser Powder Bed Fusion (LPBF)

△ Xact Metal test piece showing SLM accuracy (source: Xact Metal)

In all 3D printing technologies, this item has the most aliases. The formal name of this metal 3D printing method is laser powder bed melting (LPBF), which is also widely known as direct metal laser sintering (DMLS) and selective laser melting (SLM). In the early days of this technology development, machine manufacturers created their own names for the same process, and these names have been used to this day. In particular, these three terms refer to the same process, even though some mechanical details are different.

As a sub-type of powder bed fusion, LPBF uses a metal powder bed and one or more (up to 12) high-power lasers. LPBF 3D printer uses laser to selectively fuse metal powder layer by layer on a molecular basis until the model is completed. LPBF is a highly accurate 3D printing method, which is usually used to create complex metal parts for aerospace, medical and industrial applications.

△Sandvik’s LPBF metal 3D printing

Like SLS, LPBF 3D printers start with a digital model divided into slices. The printer loads the powder into the building chamber, and then spreads it into a thin layer on the building board with a scraper (such as a windshield wiper) or a roller. The laser tracks the layer onto the powder. Then the building platform moves down, and then a layer of powder is coated and blended with the first layer until the whole object is built. The building chamber is closed and sealed, and in many cases it is filled with inert gas, such as nitrogen or argon mixture, to ensure that the metal will not be oxidized during the melting process and help to remove the debris during the melting process. After printing, the parts are taken out of the powder bed, cleaned and often subjected to secondary heat treatment to eliminate stress. The remaining powder is recycled.

The differentiation factors of LPBF 3D printer include the type, intensity and quantity of lasers. A small compact LPBF printer may have one 30-watt laser, while the industrial version may have 12 1,000-watt lasers. LPBF machines use common engineering alloys, such as stainless steel, nickel superalloy and titanium alloy. Dozens of metals can be used in LPBF process.

△ LPBF 3D printers from One Click Metal, Farsoon and Kurtz Ersa.

3. Electron beam melting (EBM)

△ electron beam melting (EBM)

EBM, also known as Electron Beam Powder Bed Fusion (EB PBF), is a metal 3D printing method similar to LPBF, but using electron beam instead of fiber laser. This technology is used to manufacture parts, such as titanium orthopedic implants, turbine blades of jet engines and copper coils.

Electron beams generate more energy and heat, which are needed by some metals and applications. Moreover, EBM is not an inert gas environment, but is carried out in a vacuum chamber to prevent light beam scattering. The temperature of the building chamber can reach up to 1,000 °C, and even higher in some cases. Because the electron beam is controlled by electromagnetic beam, it moves faster than laser, and can even be separated to expose multiple areas at the same time.

△ Electron beam melting (EBM) metal 3D printers from JEOL, GE Additive and Wayland Additive.

One of the advantages of EBM over LPBF is that it can handle conductive materials and reflective metals such as copper. Another feature of EBM is that individual components can be nested or stacked in the building room, because they do not necessarily have to be connected to the building board, which greatly increases the volume output. Compared with laser, electron beam usually produces larger layer thickness and rougher surface features. Due to the high temperature in the building room, EBM printing parts may not need to be heat-treated after printing to relieve stress.

Fourth, material spraying

△ material injection

Material ejection is a 3D printing process in which tiny droplets of material are deposited and then solidified or solidified on the building board. Use photopolymer or wax droplets that will cure when exposed to light to build objects one layer at a time. The nature of the material spraying process allows different materials to be printed on the same object. One application of this technology is to manufacture parts with various colors and textures.

● Types of 3D printing technology: material ejection (MJ) and nanoparticle ejection (NPJ)

● Material: photosensitive resin (standard, pouring, transparent, high temperature resistant), wax.

● Dimensional accuracy: ±0.1 mm

● Common applications: full-color product prototypes, prototypes similar to injection molds, low-running injection molds, medical models, and fashion.

● Advantages: textured surface finish, full color and various materials available.

● Disadvantages: Limited materials are not suitable for mechanical parts requiring precision, and the cost is higher than other resin technologies used for visual purposes.

1. material injection (M-Jet)

△Stratasys’s material jet 3D printing parts

Material jet of polymer (M-Jet) is a 3D printing process, in which a layer of photosensitive resin is selectively deposited on the building board and cured by ultraviolet (UV). After one layer is deposited and solidified, the building platform reduces the thickness of one layer, and the process is repeated to build 3D objects. M-Jet combines the high precision of resin 3D printing with the speed of wire 3D printing (FDM) to create parts and prototypes with realistic colors and textures.

All material jet 3D printing technologies are not exactly the same. There are differences between printer manufacturers and proprietary materials. M-Jet machines deposit building materials from multiple rows of print heads in a line-by-line manner. This method enables the printer to manufacture multiple objects on a line without affecting the construction speed. As long as the models are arranged correctly on the construction platform and the space in each construction line is optimized, M-Jet can produce parts faster than many other types of resin 3D printers.

△ Material jet 3D printers from Stratasys, DP Polar/3D Systems and Mimaki.

The object made by M-Jet needs support, and it is printed by soluble materials at the same time during the construction process, which is removed in the post-processing stage. M-Jet is one of the few 3D printing technologies, which can provide objects made of multi-material printing and full color. There is no amateur version of the material jet machine. These machines are more suitable for professionals of automobile manufacturers, industrial design companies, art studios, hospitals and all kinds of product manufacturers. They want to create accurate prototypes to test concepts and bring products to market faster. Unlike barrel polymerization technology, M-Jet does not need post-curing, because the ultraviolet rays in the printer will completely cure each layer.

Aerosol jet

Aerosol Jet is a unique technology developed by a company named Optomec, which is mainly used for 3D printing electronic products. Components such as resistors, capacitors, antennas, sensors and thin film transistors are printed by aerosol spraying technology. It can be roughly compared to painting, but it is different from industrial coating process in that it can be used to print complete 3D objects.

Put the electronic ink into the atomizer, which will produce droplets with a diameter between 1 and 5 microns. Then the aerosol mist is transported to the deposition head and focused by the sheath gas, thus producing a high-speed particle spray. Because the whole process uses energy, this technology is sometimes called directional energy deposition, but because the material is in the form of droplets in this case, we include it in the material injection.

Plastic free forming

Arburg, a German company, has created a technology called plastic freeform molding (APF), which is a combination of extrusion technology and material injection technology. It uses commercially available plastic particles, which are melted in the injection molding process and moved to the unloading unit. The closing of the high-frequency nozzle produces a rapid opening and closing movement of up to 200 plastic droplets with a diameter of 0.2 to 0.4 mm per second. The droplets combine with the hardened material when cooling. Generally speaking, no post-treatment is needed. If supporting materials are used, they must be removed.

2. Nanoparticle Jet (NPJ)

△ Metal parts created by using nanoparticle injection technology and XJet 3D printer.

NanoParticle Jetting (NPJ) is one of the few proprietary technologies that are difficult to classify. It was developed by a company named XJet. It uses a printhead array with thousands of inkjet nozzles to spray millions of ultrafine material droplets onto the ultra-thin building tray at the same time, and simultaneously spray supporting materials. Metal or ceramic particles are suspended in a liquid. This process takes place at high temperature, and the liquid evaporates when spraying, leaving mostly metal or ceramic materials. Only a small amount of adhesive remains in the generated 3D parts, and these adhesives are removed in the post-sintering treatment.

V. Adhesive spraying

△ adhesive spraying

Adhesive spraying is a 3D printing process in which liquid adhesive selectively adheres to areas of a layer of powder. This technology type has the characteristics of powder bed fusion and material injection. Similar to PBF, adhesive spraying uses powder materials (metal, plastic, ceramics, wood, sugar, etc.), and like material spraying, liquid adhesive polymer is deposited from an inkjet. Whether it is metal, plastic, sand or other powder materials, the adhesive spraying process is the same.

First, the recoating blade coats a thin layer of powder on the building platform. Then, a print head with an inkjet nozzle passes over the bed and selectively deposits adhesive droplets to bond the powder particles together. After the layer is completed, the building platform moves down and the blade recoats the surface. Then repeat the process until the whole part is completed.

Adhesive spraying is unique in that there is no heat in the printing process. The binder acts as glue that binds the polymer powders together. After printing, the parts are wrapped in unused powder, which usually remains for curing. Then the parts are taken out of the powder bin, and the excess powder is collected and can be reused. From here on, according to different materials, post-treatment is needed, except for sand, which can usually be directly used as cores or molds from printers. When the powder is metal or ceramic, the post-treatment involving heating will melt the binder, leaving only the metal. Post-treatment of plastic parts usually includes coating to improve surface finish. You can also polish, paint and grind the polymer adhesive spraying parts.

The adhesive has high spraying speed and high productivity, so it can produce a large number of parts more economically and efficiently than other AM methods. Metal adhesive spraying can be used for a variety of metals and is very popular in end-use consumer goods, tools and bulk spare parts. However, the material selection of polymer adhesive injection is limited, and the structural performance of the produced parts is low. Its value lies in being able to make full-color prototypes and models.

● Subtypes of 3D printing technology: metal adhesive spraying, polymer adhesive spraying and sand adhesive spraying.

● Material: sand, polymer, metal, ceramics, etc.

● Dimensional accuracy: 0.2 mm (metal) or 0.3 mm (sand)

● Common applications: functional metal parts, full-color models, sand castings and molds.

● Advantages: low cost, large building volume, functional metal parts, excellent color reproduction, fast printing speed and unsupported design flexibility.

Disadvantages: It is a multi-step process for metals, and polymer parts are not durable.

1. Metal adhesive spraying

△ HP stainless steel 3D printing parts using metal spraying technology

Binder Jetting can also be used to manufacture solid metal objects with complex geometries, which is far beyond the capabilities of traditional manufacturing technologies. Metal adhesive spraying is a very attractive technology, which can be used to mass-produce metal parts and realize lightweight. Since adhesive spraying can print parts with complex patterns instead of solids, the weight of the parts obtained is greatly reduced, but the strength remains unchanged. The porosity characteristics of adhesive injection can also be used to realize lighter end parts for medical applications, such as implants.

Generally speaking, the material properties of metal binder sprayed parts are equivalent to those of metal parts produced by metal injection molding, and it is one of the most widely used manufacturing methods in mass production of metal parts. In addition, the adhesive spraying parts show higher surface smoothness, especially in the internal channels.

△ Metal adhesive jet 3D printer produces fine solid metal parts for end-use applications.

Metal adhesive spraying parts need secondary processing after printing to obtain good mechanical properties. Just coming out of the printer, the parts are basically composed of metal particles bonded together with polymer adhesives. These so-called "green parts" are too fragile to be used as they are. After the printed parts are taken out of the metal powder bed (called the process of powder removal), they will be heat-treated in the furnace (called the process of sintering). Both printing parameters and sintering parameters are adjusted according to the geometry, material and required density of specific parts. Bronze or other metals are sometimes used to penetrate the voids in the adhesive spraying parts, thus achieving zero porosity.

2. Plastic adhesive spraying

△ Plastic adhesive spraying

Plastic adhesive spraying is a process very similar to metal adhesive spraying, because it also uses powder and liquid adhesive, but its application is quite different. After printing, plastic parts will be taken out of their powder beds and cleaned, and usually can be used without further treatment, but these parts lack the strength and durability in the 3D printing process. The plastic adhesive spraying part can be filled with another material to improve the strength. Using polymers for adhesive spraying can produce multicolor parts for medical modeling and product prototyping.

3. Sand binder spraying

△ sand binder injection

Sand adhesive spraying and plastic adhesive spraying are different in printer and printing process, so they are distinguished here. Producing large sand casting molds, molds and cores is one of the most common uses of adhesive injection technology. The low cost and speed of this process make it an excellent solution for foundry, because it is difficult to produce fine pattern designs in a few hours with traditional technology.

The future of industrial development constantly puts high demands on foundries and suppliers. Sand 3D printing is at the beginning of its potential. After printing, the printer needs to remove the cores and molds from the construction area and clean them to remove any loose sand. The mold can usually be ready for casting immediately. After casting, the mold is disassembled and the final metal parts are removed.

4. Multi-jet fusion (MJF)

△ BASF and HP cooperated to develop a new industrial grade polypropylene for MJF.

Another unique and brand-specific 3D printing process, which is not easy to fall into any existing category, is actually not adhesive spraying, and this is HP’s Multi Jet Fusion. MJF is a polymer 3D printing technology, which uses powder materials, liquid fusion materials and refiners. The reason why it is not considered as adhesive spraying is that the heat is increased in this process, which will produce parts with higher strength and durability, and the liquid is not completely adhesive. The name of this process comes from multiple inkjet heads that perform the printing process.

In the process of Multi Jet Fusion printing, the printer lays a layer of material powder, usually nylon, on the printing bed. After that, the inkjet head passes through the powder and deposits a melting agent and a refining agent on it. Then the infrared heating device moves on the printed matter. No matter where the flux is added, the lower layers will melt together, while the areas with refiners will remain powdery. The powdery part falls off to produce the required geometry. This also eliminates the need for modeling support, because lower layers support layers printed on them. In order to complete the printing process, the whole powder bed and the printing parts in it are moved to a single processing station, and most of the loose unmelted powder is evacuated and can be reused.

Multi Jet Fusion is a multifunctional technology, which has been applied in many industries such as automobile, medical care and consumer goods.

△HP Jet Fusion 5200 series is one of the many sizes and styles of HP Multi Jet Fusion 3D printer (source: HP).

Six, powder directional energy deposition

Directional Energy Deposition (DED) is a 3D printing process. Metal materials are supplied and melted by powerful energy while being deposited. This is one of the most extensive 3D printing categories, including many subcategories, depending on the material form (wire or powder) and energy type (laser, electron beam, arc, supersonic, heat, etc.). Essentially, it has a lot in common with welding.

This technology is used for layer-by-layer printing, usually followed by CNC machining to achieve stricter tolerances. The combination of DED and CNC is very common. There is a sub-type of 3D printing called hybrid 3D printing, which contains a hybrid 3D printer with DED and CNC units in the same machine. This technology is considered to be a faster and cheaper substitute for small-batch metal castings and forgings, as well as a key maintenance for offshore oil and gas industries, aerospace, power generation and utilities.

△DED metal 3D printing technology can quickly create a solid metal part, and then it can be processed to strict tolerances.

● Subtypes of directional energy deposition: powder laser energy deposition, wire arc additive manufacturing (WAAM), wire electron beam energy deposition and cold spraying.

● Materials: various metals, wires and powder forms.

● Dimensional accuracy: ±0.1 mm

● Common applications: repairing high-end automotive/aerospace components, functional prototypes and final components.

● Advantages: high stacking rate, and the ability to add metal to existing components.

● Disadvantages: Because the supporting structure cannot be made, it is impossible to make complex shapes, and the surface smoothness and accuracy are usually poor.

1. Laser directed energy deposition

△ 3D printing metal using laser and powder metal

Laser-directed energy deposition (L-DED), also known as laser metal deposition (LMD) or laser engineering net shaping (LENS), uses metal powder or metal wire sent through one or more nozzles and melted by powerful laser to build platforms or metal parts. With the movement of nozzle and laser or the movement of parts on the multi-axis turntable, objects will be piled up layer by layer. The construction speed is faster than that of powder bed melting, but it will lead to the decrease of surface quality and precision, and usually requires a lot of post-processing. Laser DED printers usually have a sealed chamber filled with argon to avoid oxidation. When dealing with less reactive metals, they can also operate with only local argon or nitrogen.

Metals commonly used in this process include stainless steel, titanium and nickel alloy. This printing method is usually used to repair high-end aviation and automobile parts, such as jet engine blades, but it is also used to produce whole parts.

△Meltio M450 wire feeding laser DED 3D printer, Optomec LENS CS 600 metal powder feeding laser DED 3D printer and DMG Mori Lasertec 65 DED powder feeding laser DED 3D printer.

2. Electron beam directional energy deposition

△ electron beam DED 3D printing

Electron beam DED, also known as linear electron beam energy deposition, is a 3D printing process very similar to laser DED. It is carried out in a vacuum chamber and can produce very clean and high-quality metals. When a wire passes through one or more nozzles, it will be melted by the electron beam. The layer is constructed separately, the electron beam forms a tiny molten pool, and the welding wire is fed into the molten pool by a wire feeder. When dealing with high-performance metals and active metals (such as copper, titanium, cobalt and nickel alloy), electron beam is selected for DED.

DED machines are virtually unlimited in print size. For example, Sciaky, a 3D printer manufacturer, has an EB DED machine that can produce parts nearly 6 meters long at a speed of 3 to 9 kilograms of materials per hour. Electron beam DED is touted as one of the fastest methods to manufacture metal parts, although it is not the most accurate, which makes it an ideal machining technology to build large structures (such as fuselage) or replace parts (such as turbine blades).

△ 3D printing of wire by electron beam deposition

3. Line-controlled energy deposition

△Gefertec arc additive manufacturing (WAAM) printing

Wire Directed Energy Deposition, also known as wire arc additive manufacturing (WAAM), is a kind of 3D printing, which uses energy in the form of plasma or arc to melt the metal in the form of wire, and deposits the metal layer by layer on a surface, such as a multi-axis turntable, to form a shape by a robotic arm. This method is chosen instead of the similar technology of laser or electron beam because it does not need a sealed chamber and can use the same metal (sometimes the same material) as traditional welding.

Direct energy deposition is considered to be the most cost-effective choice in DED technology, which can use the existing arc welding robot and power supply, so the entry threshold is relatively low. But unlike welding, this technology uses complex software to control a series of variables in the process, including the thermal management of the robot arm and the tool path. This technology has no supporting structure to be removed, and the finished parts are usually CNC machined when necessary to achieve strict tolerance or surface polishing.

△Gefertec and WAAM3D’s line arc additive manufacturing 3D printer.

4. Cold spraying

△ cold spraying

Cold spraying is a DE3D printing technology, which sprays metal powder at supersonic speed to combine them without melting, and hardly produces thermal cracks or thermal stress. Since the early 2000s, it has been used as a coating process, but recently, several companies have used cold spraying for additive manufacturing, because it can print at a speed 50 to 100 times higher than that of a typical metal 3D process and does not require inert gas or vacuum chamber.

Like all DED processes, cold spraying will not produce prints with good surface quality or details, but the parts can be used directly from the printing bed.

5. Melting direct energy deposition

△ Melting Direct Energy Deposition: Aluminum parts printed by ElemX 3D liquid metal of Xerox.

Melting direct energy deposition is a 3D printing process, which uses heat to melt metal (usually aluminum) and then deposits it layer by layer on the building board to form 3D objects. The difference between this technology and metal extrusion 3D printing is that metal raw materials containing a small amount of polymer are used for extrusion, so that the metal can be extruded. Then the polymer is removed in the heat treatment stage, and pure metal is used to melt DED. One can also compare molten or liquid DED to material injection, but instead of a series of nozzles to deposit droplets, liquid metal usually flows out from the nozzles.

Variants of this technology are being developed, and molten metal 3D printers are rare. The advantage of using heat to melt and then deposit metal is that it can use less energy than other DED processes, and it is possible to directly use recycled metal as raw material instead of metal wire or highly processed metal powder.

VII. Lamination of sheets

△ Sheet lamination

Sheet lamination is technically a form of 3D printing, which is quite different from the above technologies. Its function is to stack and laminate very thin pieces of material together to create 3D objects or stacks, and then cut them by machinery or laser to form the final shape. The layers of materials can be fused together in a variety of ways, including heating and sound, depending on the material, ranging from paper to polymer to metal. When the parts are laminated and then laser cut or processed into the required shape, it will produce more waste than other 3D printing technologies.

Manufacturers use sheet lamination to produce cost-effective non-functional prototypes at a relatively high speed, which can be used in battery technology and composite materials, because the materials used can be interchanged in the printing process.

● Types of 3D printing technology: Laminated Object Manufacturing (LOM) and Ultrasonic Consolidation (UC)

● Materials: paper, polymer and sheet metal.

● Dimensional accuracy: ±0.1 mm

● Common applications: non-functional prototyping, multi-color printing and casting.

● Advantages: rapid production and compound printing.

● Disadvantages: low precision, much waste, and some parts need post-production.

Laminated additive manufacturing

△ Laminated additive manufacturing

Lamination is a 3D printing technology, in which sheets of materials are laminated and glued together, and then the layered objects are cut into the correct shape with a knife (or laser or CNC router). This technology is less common nowadays, because the cost of other 3D printing technologies has decreased, and the speed and ease of use have greatly increased.

△BCN3D viscous lithography manufacturing (VLM) 3D printing process using resin (source: BCN3D)

Viscosity lithography (VLM): VLM is a patented 3D printing process of BCN3D, which can laminate a thin layer of high-viscosity photosensitive resin onto a transparent transfer film. The mechanical system allows the resin to be laminated from both sides of the film, so that different resins can be combined to obtain a multi-material part and an easily detachable support structure. This technology has not been commercialized, but it can also belong to one of the laminated 3D printing technologies.

Composite-based additive manufacturing (CBAM):Startup Impossible Objects applied for a patent for this technology, which combines carbon, glass or Kevlar mats with thermoplastics to manufacture parts.

Selective Laminated Composite Manufacturing (SLCOM): Envision Tec, now called ETEC, owned by Desktop Metal, developed this technology in 2016, which uses thermoplastics as the base material and woven fiber composite.

Note: There are many kinds of 3D printing technologies. These are the seven most common additive manufacturing technologies in 3D printing, which do not cover all 3D printing technologies in the market.

Original title: "7 mainstream 3D printing technologies, all of which can be understood"

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