Cho Chulmin, Shin Wooseop, Kim Minwoo, Bang Junhyuk, Won Phillip, Hong Sukjoon, Ko Seung Hwan
Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
Mechatronics Research, Samsung Electronics, 1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do, 18848, South Korea.
Small. 2022 Sep;18(37):e2202841. doi: 10.1002/smll.202202841. Epub 2022 Jul 28.
Owing to its low mechanical compliance, liquid metal is intrinsically suitable for stretchable electronics and future wearable devices. However, its invariable strain-resistance behavior according to the strain-induced geometrical deformation and the difficulty of circuit patterning limit the extensive use of liquid metal, especially for strain-insensitive wiring purposes. To overcome these limitations, herein, novel liquid-metal-based electrodes of fragmented eutectic gallium-indium alloy (EGaIn) and Ag nanowire (NW) backbone of which their entanglement is controlled by the laser-induced photothermal reaction to enable immediate and direct patterning of the stretchable electrode with spatially programmed strain-resistance characteristics are developed. The coexistence of fragmented EGaIn and AgNW backbone, that is, a biphasic metallic composite (BMC), primarily supports the uniform and durable formation of target layers on stretchable substrates. The laser-induced photothermal reaction not only promotes the adhesion between the BMC layer and substrates but also alters the structure of laser-irradiated BMC. By controlling the degree of entanglement between fragmented EGaIn and AgNW, the initial conductivity and local gauge factor are regulated and the electrode becomes effectively insensitive to applied strain. As the configuration developed in this study is compatible with both regimes of electrodes, it can open new routes for the rapid creation of complex stretchable circuitry through a single process.
由于其较低的机械柔顺性，液态金属本质上适用于可拉伸电子器件和未来的可穿戴设备。然而，其随应变诱导的几何变形而不变的应变电阻行为以及电路图案化的困难限制了液态金属的广泛应用，特别是在应变不敏感布线方面。为了克服这些限制，本文开发了一种新型的基于液态金属的电极，它由破碎的共晶镓铟合金（EGaIn）和银纳米线（NW）骨架组成，其缠结通过激光诱导的光热反应来控制，从而能够直接即时地对具有空间编程应变电阻特性的可拉伸电极进行图案化。破碎的EGaIn和AgNW骨架的共存，即双相金属复合材料（BMC），主要支持在可拉伸基板上均匀且持久地形成目标层。激光诱导的光热反应不仅促进了BMC层与基板之间的粘附，还改变了激光辐照的BMC的结构。通过控制破碎的EGaIn和AgNW之间的缠结程度，可以调节初始电导率和局部应变系数，并且电极对施加的应变变得有效不敏感。由于本研究中开发的配置与两种电极模式都兼容，它可以通过单一过程为快速创建复杂的可拉伸电路开辟新途径。
