Edible and Recyclable Gelatin-Based Electronics for High-Precision Health and Environmental Monitoring

Edible electronics represent a transformative class of sustainable technologies that combine functionality, safety, and environmental transience. Here, a multifunctional, edible, and recyclable sensor film is presented composed of gelatin and activated charcoal-two naturally abundant and food-safe materials-engineered for high-precision health and environmental monitoring. These free-standing composite films exhibit a phase-separated bilayer structure, enabling the integration of an insulating gelatin top layer with a conductive charcoal-rich bottom layer. At an optimal filler loading of 10 wt%, the films achieve a tensile strength of 60 MPa and electrical conductivity of 0.04 S m^-1, supporting multimodal sensing of strain (gauge factor 3.8, response time 120 ms, stable over 10 000 cycles), humidity (40-95% RH), and temperature (0-90 °C). Demonstrations include real-time motion tracking, respiration monitoring, speech recognition, and contactless thermal sensing. Uniquely, the films degrade fully in soil within three weeks or can be recycled in water without loss of mechanical or electrical performance. This work advances the design of sustainable materials that combine performance and sustainability, offering a scalable pathway toward circular electronics for a zero-waste future.