Gallium‐Based Thin Films for Wearable Human Motion Sensors

Wearable electronic circuits based on the films of gallium and its alloys offer promising implementations in health monitoring and gaming sensing applications. However, the complex rheology of liquid metals makes it challenging to manufacture thin gallium‐based devices with reliable, reproducible, and stable properties over time. Herein, the surface coating and topography of silicone substrates are engineered to enable precisely defined, micrometer‐thick liquid metal patterns over large (>10 cm2) surface areas, and high design versatility. Control over the film microstructure meets manufacturing conditions that enable gallium films with a precise, repeatable, and durable electromechanical performance. The robustness and applicability of this technology in a virtual‐reality scenario is demonstrated by implementing thin, soft, and stretchable gallium‐based sensors to accurately monitor human hand kinematics.