echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Research group of Professor Liu Jing of Tsinghua University: liquid metal composite materials with reversible transition characteristics of ultra-high tensile conductor insulator

    Research group of Professor Liu Jing of Tsinghua University: liquid metal composite materials with reversible transition characteristics of ultra-high tensile conductor insulator

    • Last Update: 2019-05-07
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com
    The materials that lead to the rapid transition between conductor and insulator are of great value in theoretical research and industrial application The traditional conductor insulator transition materials are mainly concentrated in solid materials such as vanadium dioxide, perovskite, organic film and so on, which need more complex preparation process and stimulation conditions, which limits its wider application Recently, based on liquid metal and silica gel materials at room temperature, Professor Liu Jing's research group of Tsinghua University invented and developed a composite material (TIC) which can realize the conductor insulator transition function The corresponding transition is not only reversible, but also can be repeated more than 100 times without obvious structural damage The maximum tensile range can reach 780% of the original length This kind of material has a simple preparation process and can be printed in 3D It is of great significance for the development of flexible and stretchable semiconductor devices, temperature switches, intelligent wearable devices and even sensors for extreme environmental detection in outer space in the future The corresponding results were published in the international authoritative journal advanced materials (DOI: 10.1002 / ADMA 201901337) Wang Hongzhang, 2015 and Yao Youyou, 2014, PhD students of Tsinghua University School of medicine, are the co authors of this paper Professor Liu Jing of Tsinghua University is the corresponding author of this paper Prof Liu Jing, the research group has been engaged in the interdisciplinary research of liquid metal, biomedical engineering and Engineering Thermophysics for a long time and made a series of pioneering contributions Many new scientific phenomena, basic effects and transformative application approaches of liquid metals have been discovered, which has opened up breakthrough applications of liquid metals in biomedical, flexible robots, printing electronics, 3D printing, advanced energy, chip cooling and other fields The results have wide influence in the world, and have been widely used in many scientific magazines such as MIT Technology Review, Many liquid metal application systems, high-end tumor minimally invasive treatment equipment and wireless mobile medical instruments have entered the market At present, the team has 51 members, including 7 postdoctors, 24 doctoral students and 10 masters Prof Liu Jing, Professor, Department of Biomedical Engineering, School of medicine, Tsinghua University, researcher, Institute of physical and chemical technology, Chinese Academy of Sciences Tsinghua University Bachelor of Engineering (Department of activity), Bachelor of Science (Department of Physics) and doctor of Engineering (Department of activity); he was a postdoctoral scholar of Purdue University and a senior visiting scholar of Massachusetts Institute of technology in the United States, and has been selected into the Chinese Academy of Sciences and Tsinghua University hundred talents program He is the winner of the National Science Foundation for Distinguished Young Scholars in 2003; he has won one of the highest awards in the international heat transfer industry, "the William begell Medal", the first national innovation award, the first prize of technological invention of the Chinese refrigeration society, the only best paper award of the year in the Journal of electronic packaging of ASME, shortlisted and selected into the "top ten science and technology progress news of China selected by academicians of the two academies" 1 Second, he was selected as CCTV's top 10 scientific and technological innovation figures in 2015 He has published 14 interdisciplinary cutting-edge works (one of which has been printed 5 times) and 20 chapters of invited works; published more than 500 Journal Papers (including more than 30 English cover or back cover stories); and has obtained more than 190 authorized invention patents Cutting edge scientific research achievements: liquid metal composite materials with reversible transition characteristics of ultra-high tensile conductor insulator is a kind of metal that presents liquid state at room temperature, with outstanding characteristics such as high surface tension, high boiling point, strong conductivity and high thermal conductivity Based on many years of liquid metal research foundation, Liu Jing's research group found through a large number of experimental studies, When liquid metal is mixed with silica gel material with specific viscosity in a certain proportion, it can naturally solidify to form composite material The liquid metal microparticles in the material are surrounded by silica gel, which shows insulation characteristics at room temperature However, when the material is triggered by low temperature, it can change from insulation state to conductor, and the insulation state can be restored after the material is heated up (Fig 1) It is worth noting that this transformation process can be repeated more than 100 times without obvious structural damage and electrical performance change In the whole process, the material can be stretched repeatedly, and the fast insulator conductor transition can still be realized in the stretching state Fig 1 the reversible conductor insulator transition of tensile materials under temperature stimulation (source: Advanced Materials) further study found that the volume of liquid metal (gallium indium alloy) will increase correspondingly during solidification Due to the isolation of the insulated silica gel, the liquid metal micro particles initially show the insulation characteristics Under the action of low temperature, the conductive liquid metal undergoes phase transformation and solidification, and at the same time appears rapid expansion On the contrary, the insulating silica gel shrinks under the stimulation of low temperature, so the liquid metal particles are extruded out of the silica gel film to form interconnection, thus showing the conductivity After heating, the silica gel recovers its elasticity, while the liquid metal particles melt from the solid to the liquid, resulting in the volume reduction, and then return to the state of being wrapped by silica gel, showing the insulation properties (Fig 2) Fig 2 mechanism of low temperature induced reversible conversion of gold insulator conductor (source: Advanced Materials) to verify the performance of new materials as temperature switches, the research team also specially designed and manufactured a tic based circuit placed inside the 4WD, which is insulated at room temperature When the tic is frozen, the 4WD starts running immediately When the tic material recovers the room temperature, the circuit is automatically disconnected, and the 4WD stops moving (Figure 3) Fig 3 low temperature switch display (source: Advanced Materials) Furthermore, the article also shows that the display device which can realize different pattern functions through the change of environment temperature is developed by using tic material as temperature sensor, combining single-chip microcomputer and Bluetooth device As shown in Figure 4, changing the temperature can display the English initial Thu and 0-9 Arabic numerals of Tsinghua University Figure 4 temperature control display device based on TiC material (source: Advanced Materials) is worth mentioning that the insulator conductor transition characteristics of the material under low temperature stimulation are still expected to be used in lunar exploration In the extremely low temperature environment of the moon at night, the material changes from an insulator to a conductor, which connects the circuit to carry out the work; while in the day when the temperature of the moon rises, the material returns to the insulation state, the switch is disconnected, and the equipment stops working, which does not need to load the complex embedded control system The first unit of this paper is Tsinghua University School of medicine This research is supported by the key project "Research on soft sensing robot technology with liquid metal software" of NSFC, the dean's fund of Chinese Academy of Sciences and the frontier project Nowadays, people and scientific research have been paid more and more attention in the economic life China has ushered in the "node of science and technology explosion" Behind the progress of science and technology is the work of countless scientists In the field of chemistry, in the context of the pursuit of innovation driven, international cooperation has been strengthened, the influence of Returned Scholars in the field of R & D has become increasingly prominent, and many excellent research groups have emerged in China For this reason, CBG information adopts the 1 + X reporting mechanism CBG information, chembeangoapp, chembeango official microblog, CBG wechat subscription number and other platforms jointly launch the column of "people and scientific research", approach the domestic representative research group, pay attention to their research, listen to their stories, record their demeanor, and explore their scientific research spirit.
    This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

    Contact Us

    The source of this page with content of products and services is from Internet, which doesn't represent ECHEMI's opinion. If you have any queries, please write to service@echemi.com. It will be replied within 5 days.

    Moreover, if you find any instances of plagiarism from the page, please send email to service@echemi.com with relevant evidence.