Biocompatible liquid metal coated stretchable electrospinning film for strain sensors monitoring system

Liquid metals (LMs) are potential inorganic materials which could be applied in flexible and deformable electronics owing to their fluidity, low viscosity, high metallic conductivity, toxicity. However, recently reported sensing devices based on LMs required complex processes with cost. Herein, a three-dimensional (3D) conductive network was prepared by coating LM droplets onto an electrospun thermoplastic polyurethane (TPU) fiber film. The is suspended between the TPU fibers self-coalesces into vertically buckled laterally mesh-like structure, provides good biocompatibility, stretchability simultaneously. LM-TPU composite-film-based device demonstrates multitude of desired features, such as widely workable stretching range (0%–200%), sufficient sensitivity under strain (gauge factor (GF) 0.2 at 200% strain), outstanding stability durability (9000 cycles). In vitro biocompatibility experiments show that composite film directly attached skin has excellent biocompatibility. Such sensor-based integrated monitoring systems monitor human body motions real time, muscle movement joint motion, revealing application prospects healthcare human-machine interfacing.