Nano-structured stretchable electrode using liquid metal and its applications

Abstract

Stretchable electronics are essential for the next-generation electronic devices such as wearable devices, stretchable displays, stretchable optoelectronics, and bio-sensors. Therefore, researches of electrodes that have stretchability are currently being reported. Here, we introduce a facile fabrication method for the stretchable electrode by using physical vapor deposition (PVD) of liquid metal. By using this method, indium and gallium nanoclusters form an overlayered structure that can facilitate a conductive network. This electrode has a unique property that the change in electrical resistance decreases under the tensile strain. A complementary strain sensor was demonstrated using this electrode with a conventional strain gauge. Moreover, since this electrode can be patterned by various patterning processes, nano-structures are adapted to fabricate a stretchable and transparent electrode. A mesh structured electrode was fabricated by conventional photolithography and transfer process, and a random nanonetwork structured electrode was fabricated by using the electrospinning process and a sacrificial layer. With these nanostructure-based approaches, a highly stretchable and transparent electrode using liquid metal is demonstrated.