The research group led by Prof. Seung Hwan Ko, in Dept. of Mechanical Engineering in Seoul National University, developed liquid metal based stretchable room temperature soldering sticker patch

The research group led by Prof. Seung Hwan Ko, in Dept. of Mechanical Engineering in Seoul National University developed a stretchable soldering sticker patch based on liquid metals that can be used at room temperature.

Recently, the technology related to stretchable electronics, which is indispensable to the wearable, robotic and bio industries, has gained a global attention. Researchers around the globe are spending lots of energy to endow stretchability to existing electronics. But despite these efforts, the commercialization of stretchable electronics has not yet been achieved. The reason is that despite stretchable electrodes have been newly condensed, the integration with various SMD chips for information processing, communication, sensing, etc. is seriously unstable. A stress concentration occurs on the interface of the hard chip and the soft electrode, which eventually breaks the electrical connection.

The researcher group used the freestanding liquid metal-nanowire composite to solve the surface failure problem that occurs between hard chips and soft electrodes. The composite has more than 800% elasticity, electrical conductivity similar to that of metals, and negligible contact resistance . The researchers used these freestanding composites to solder between elastic electrodes and hard chips to solve a problem that was impossible to resolve in the existing stretchable electronics.

Not only this, but the newly developed soldering sticker patch can also be utilized to directly solder the elastic electrodes and hard chips placed on the skin. Through this technique, a temperature/humidity sensor was installed on the nails, and a LED was placed on the biocompatible electrodes on the hand. It also facilitated the installation of temperature and pressure sensors on a finger to measure the temperature of objects touched by the finger, and send a moss signal.

Professor. Seung Hwan Ko referred, “We hope that this achievement will solve the problems in stretchable electronics, which had previously been a significant problem, and will be used in a variety of future industries such as wearables electronics, robotics, and bioindustry.”

The research results have received the worldwide attention and were published online on May 11, 2023 in <Advanced Functional Materials>, an academic journal in the field of materials science. (Liquid Metal based Stretchable Room Temperature Soldering Sticker Patch for Stretchable Electronics Integration)

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