Hot Spot Perspective · Leaping over the future, innovation carries the dream of making the country strong through science and technology, liquid metal: trillion-level industrial aircraft carrier to be accelerated

【CCN】Which fields are liquid metal mainly used in, and what are the advantages compared with traditional materials?

[Liu Jing] Liquid metal refers to a metal that is liquid, flowable and conductive at room temperature. Liquid metal is both a metal and a liquid, which is equivalent to the superposition of various functional materials, so it has applications in many fields. In the field of thermal control, liquid metal is used to make thermal paste for chip cooling and computer device heat dissipation. It has a high boiling point and fast heat transfer. Compared with traditional materials, the thermal conductivity has been changed by orders of magnitude ; radiators made of liquid metal It can solve the global problem of thermal barrier that cannot be solved by traditional materials, and has formed its unique theory and technical system.In the electronics field, liquid metal can be used as ink for 3D printing to directly generate electronic circuits. Compared with traditional metals, its printing temperature and equipment cost are greatly reduced, and the manufacturing time is shortened, which can be customized. In the medical field, liquid metal has good biocompatibility with the human body, and can connect nerve electrical signals to repair broken nerves. In the field of machinery, compared with traditional polymer materials, liquid metal is self-driven, deformable, capable of running and jumping , providing a path for the development of flexible robots. The above application fields were all pioneered by Chinese researchers, and they have aroused considerable international response.

[CCN] At present, what is the level and stage of domestic liquid metal research and development? Which liquid metal products and technologies have been industrialized?

[Liu Jing] In recent years, the research and development of liquid metal in China has been advancing very rapidly, and there is a broad space for scientific research in the future. The center of scientific research and industrial application of liquid metal in the world is gradually forming in China. China's liquid metal scientific research has been brewing since 2000, and more than 200 invention patents have been declared for more than ten years, covering many fields of liquid metal. The team has so far been fortunate to have made more than 40 new basic scientific discoveries, and made a series of achievements in chip cooling, heat capture, low-cost hydrogen production, desktop electronic printers, 3D printing, neural connections, tumor treatment, and flexible and variable machines. Breakthrough in underlying technology. For example, in electronic technology, my country made a major technological breakthrough in the field of printed electronics in 2014, and successfully developed the world's first room temperature liquid metal printer, which can draw circuits on any surface. In 2016, following the development of a deformable liquid metal machine that moves autonomously, we discovered that liquid metal has an "endocytosis effect" similar to cells engulfing foreign particles, which makes it possible to create "terminator" materials. Recently, Chinese researchers have put forward the concept and method of "liquid metal suspension 3D printing" for the first time, which can quickly manufacture three-dimensional flexible metal deformable bodies with arbitrary complex shapes and structures at room temperature and use them to assemble three-dimensional stretchable electronic devices. Up to now, the industrialization of liquid metal has achieved fruitful results in the fields of additive manufacturing, thermal control and energy, medical and health, and flexible machines. The "Second Liquid Metal Industry Technology Summit Forum" held in Yunnan in 2016 showcased more than 100 new products. Among them, many thermal control products have achieved large-scale sales, such as thermal interface materials, IBM in the United States and Europe All have developed thermal interface materials, but none of them can solve the problem of adhesion. The performance of thermal interface materials independently developed by China is in a leading position in the world, and a large-scale production line of up to hundreds of tons has been established. Liquid metal cooling The radiator (heat sink) has also been industrialized a few years ago, but because there are fewer and fewer desktops on the market, the production is gradually reduced. In the future, more research and development for data centers, high-performance servers, notebooks Coolers for computers and more ultra-high-power photovoltaic devices.

[CCN] Could you please briefly introduce the status quo of my country's liquid metal industry. Why can this industry shine in Yunnan?

[Liu Jing] A series of major application technologies of liquid metal are reshaping a new industrial structure and spawning a series of emerging industries. At present, China's liquid metal industry is in a very significant leading position in the world, and its products are advancing rapidly on a large scale, and there is huge room for industrial development in the future. Among them, Yunnan's liquid metal industry leads the country, forming a pattern of exporting technology, products and services.A production line with an annual output of 200 tons of liquid metal, thermal interface material products, liquid metal electronic inks, and an annual output of 200,000 sets of liquid metal electronic stylus pens has been built locally. Related products have been put on the market in batches and exported to European and American countries; the world's first Taiwan liquid metal desktop electronic circuit printers and ink cartridge production lines are also under construction. The liquid metal industry has blossomed in Yunnan for many reasons. Known as the "kingdom of non- ferrous metals", Yunnan has huge metal reserves. Among them, the reserves of 25 minerals such as lead, zinc, tin, phosphorus, copper, and silver rank among the top three in the country,which effectively provides raw materials for the industry.The strong support of the local government in Yunnan and the entrepreneurial vision, pragmatism and hard work have achieved industrial prosperity. Yunnan's natural environment and ecological environment are extremely good, attracting liquid metal companies from all over the country to gather there; its unique natural conditions also provide a good experimental platform for scientific researchers. Although Yunnan is located in the southwest, it has always maintained close ties with the capital's scientific research institutions (Tsinghua University, Chinese Academy of Sciences, etc.), realizing the organic integration of production, teaching and research, creating the wonder of "research out of Zhongguancun and industry out of Yunnan".For a high-tech industry to achieve sound development, science must advance, and industry must advance. Local support is indispensable and communication with the outside world is indispensable. Only in this way can an outward-looking, inclusive and open industrial system be formed . The above conditions have been met in the Yunnan area, which makes the liquid metal shine in the local area.

[CCN] What disruptive technologies that liquid metal is expected to produce in the future to change the world? What are the applications in the chemical and energy fields?