Selective Patterning of Liquid Metal-Based Soft Electronics via Laser-Induced Graphene Residue

Liquid metal-based flexible and stretchable electronics have the ability to sense, power, and communicate, making them suitable for non-intrusive wearable devices for monitoring of and augmenting human activities in everyday life. However, incorporating these functionalities into body sensor networks is challenging due to limitations in fabrication methods that are both high throughput and accessible, as well as the durability of the materials used, which need to withstand repeated mechanical stresses in daily use. In this study, we present a novel approach to patterning liquid metal using laser-induced graphene residue as a non-wetting barrier. The proposed method can resolve liquid metal traces up to 200 μm wide. The electrical and mechanical properties of the liquid metal traces enable these electronic devices to stretch up to 40% and bend with radii as small as 5mm, ensuring reliable connectivity for wearable human-machine interfaces. Furthermore, by transferring optimized liquid metal patterns onto a PDMS substrate, we successfully demonstrate a range of soft electronic devices that enable accessible and conformal interface with the human body without mechanical limitations.