Leather-based flexible self-powered humidity sensors for respiratory monitoring

Abstract

Numerous research studies have shown that wearable electronic devices play essential roles in health management. Sensors are inevitable in wearable electronics but always need separate power sources. Combining power generation technologies with sensors to develop self-powered sensing is significant in intelligent electronics. In this work, we designed a leather-based power generation humidity sensor driven by the electrochemical principle. Combined with the excellent hydrophilicity and ionic conductivity of leather and hygroscopicity of NaCl, the leather-based humidity sensor shows a wide humidity detection range at a relative humidity (RH) of 11–97%, an output of 0.75 V at 97% RH with a power of 8.798 µW cm⁻². In addition, the sensor can be utilized to visualize respiratory rates. Furthermore, through the integration of sensors, it can output stable voltage and charge a capacitor, proving its potential self-powered characteristic. This work proposes a convenient, economical, and eco-friendly leather-based power generation humidity sensor and demonstrates its possible applications in health management.