Biodegradable Transient Airflow Sensor Toward Eco-Friendly Implant for Respiration Monitoring

Animal experiments are essential in drug development, providing critical insights into a drug's efficacy, safety, and physiological effects before progressing to human clinical trials. In this context, we present a novel biodegradable airflow sensor designed for eco-friendly respiratory monitoring during animal studies. The sensor features a molybdenum (Mo) thin film patterned onto a flexible polyvinyl alcohol (PVA) substrate. We conducted a detailed investigation of Mo thin film deposition and achieved a temperature coefficient of resistance (TCR) of −2,063 ppm/°C through precise microstructuring. The sensor operated via Joule heating and employed constant current anemometry for airflow detection. Notably, the device fully degraded within 30 s when immersed in water, demonstrating its potential as a safe and environmentally friendly implant for temporary monitoring applications.