Self-powered flexible and transparent smart patch for temperature sensing

Wearable electronics that can deform with human skin and monitor physical information are promising next-generation electronics. Here, we demonstrate a self-powered smart patch for temperature sensing by integrating a triboelectric nanogenerator, power management circuit and temperature sensor together. Benefitting from the functional nanomaterial and fabrication process of spray coating, the main part of the device shows extraordinary mechanical flexibility and visible transparency. The temperature sensor presents a high sensitivity of 0.54% per Kelvin scaled by relative resistance change. Owing to the high efficiency of the implemented power management circuit, a capacitor of 100 μF can be easily charged to 1 V within 105 s through the triboelectric nanogenerator contacting with cotton, which can drive the sensor continuously to work for more than 100 s. The large-scalable fabrication process and integration design give this smart patch potential applications in human-machine interfaces and soft electronic skins.