Superhydrophobic surfaces-based redox-induced electricity from water droplets for self-powered wearable electronics

摘要

Making use of water energy is an attractive, renewable and clean way to derive some electronic devices. Although flowing water droplets can be utilized to generate electric signals, the corresponding origins are still unclear due to the fluid-flow-induced various effects, while generating electricity from static water droplets still remains a challenge. Here, we report redox-induced electricity from static water droplets for self-powered wearable electronics, where superhydrophobic surfaces with nanostructures not only can be utilized to enhance the output current, but also can increase the output stability. The fabricated device can deliver an output voltage of about 0.78 V and an output current of about 0.25 mA with a corresponding power density of about 30 mW/cm(3) by using a 10-mu L water droplet. Only three water droplets can be utilized to directly drive a wearable watch and sustainably power a temperature sensor for monitoring temperature variations of a human hand.