Ultra-Flexible, Anti-Freezing, and Adhesive Collagen Fiber-Derived Conductive Organohydrogel E-Skin for Strain, Humidity, Temperature, and Bioelectric Sensing Applications

The development of biomimetic electronic skin (e-skin) has significant value in many fields, including health monitoring, soft robotics, wearable electronic devices, and human-machine interaction. As a potential candidate for e-skin, the application of conductive hydrogel is limited by many factors, such as a complicated fabrication process, insufficient mechanical performance, poor environmental stability, and difficulty in degradation. Here, we adopted a top-down strategy to construct a multifunctional collagen fiber-derived conductive organohydrogel e-skin, in which the collagen fiber scaffold of goatskin was filled with a polyacrylamide network. This organohydrogel displayed excellent fracture stress (2.87 MPa) and fracture strain (542%). It could maintain its multifunctionality even at -20 degrees C and after long-term storage. Additionally, this organohydrogel demonstrated considerable adhesion and antibacterial properties, allowing it to conform closely to human skin without causing bacterial infection. The e-skin sensors, assembled with this organohydrogel, possessed multiple stimuli-responsive modes to achieve strain, humidity, temperature, and bioelectric responsiveness, allowing for the precise monitoring of body movements, facial expressions, voice communication, and physiological signals. Notably, the discarded e-skin could be effectively degraded under natural environmental conditions. In brief, this study gives new opinions about the development of intelligent multifunctional e-skin and demonstrates a new pathway for the high-value utilization of animal skin.