Wet‐Adhesive Elastomer for Liquid Metal‐Based Conformal Epidermal Electronics

Wearable electronics are increasingly used in health monitoring and treatment in different conditions. However, few devices can adhere conformally to the skin after sports and showers (sweating, deformation, friction). Here, a facile method is presented by providing a metal‐polymer conductor (MPC) made with polyethylene glycol (PEG) blended polydimethylsiloxane (PDMS) based adhesive (PPA) that encapsulates gallium‐based liquid metal alloy circuits as epidermal electronics. Adding PEG into PDMS prepolymer can result in a softer and wet‐adhesive elastomer that can bear larger deformation than PDMS itself. The soft and adhesive electronics can adhere to the skin conformally for more than 2 d. It has been demonstrated that these electronics can meet the needs of motion detection, electrophysiological signal detection and skin wound healing during a 48 h wearing with sports and shower. It is expected that the wet‐adhesive electronic with excellent biosafety can be widely used and solve existing problems in medical adhesives and human–machine interfaces. A metal‐polymer composite electronics is fabricated using gallium‐based liquid alloy circuits and polyethylene glycol‐blended polydimethylsiloxane adhesive elastomers. The soft, biocompatible, and wet‐adhesive electronics can maintain conformal adhesion with skin for more than 48 h with sweat and deformation. The application of the device in biomedical fields like joint motion, electrophysiology, and wound healing shows its potential in accurate healthcare monitoring and treatment.