Facile printing of liquid–metal-based stretchable conductor using EGaIn/Ga₂O₃ composite

Abstract

Printing gallium-based liquid metals (LMs) poses a significant challenge due to their high surface tension. In this work, we introduce a printable LM-based conductor using an EGaIn/Ga2O3 composite. This composite is achieved through a simple mixing process and is suitable for scalable stencil printing. The blend ratio of EGaIn/Ga2O3 is optimized to create LM pastes with an excellent balance of printability and electromechanical performance. Using these developed LM pastes, we successfully demonstrate a stretchable strain sensor with a gauge factor of 2 for monitoring human hand gestures. Additionally, we showcase a stretchable LED array deformable for up to 100% strain.