Stretchable Liquid Metal Wiring with Three-Dimentional Helical Structure

Abstract

In this study, stretchable liquid metal(Galinstan) wiring with three-dimensional(3D) coil was developed for preventing the resistance change during device deformation. Previously, core-shell hydrogel microsprings was fabricated using a double bevel-tip nozzle ^[1] . In this study, liquid metal as conductive liquid was injected into core part composed of starch in the microsprings. Then, 3D coil with liquid metal was developed. In stretchable and flexible electronics, it is crucial to prevent change of electrical parameters, in particular resistance in direct current(DC) and impedance in alternating current(AC), during device deformation. The developed metal wiring maintained stable resistance (less than 1.2 % difference) during 100 % tension and stable impedance(less than 0.2%) from 1 to 100k Hz in AC. As a result, we realized liquid metal wiring which is highly stable to device deformation. This report will present an important advancement towards the realization of "liquid-state" electronic system with liquid meal.