A high-current and tunable moisture-enabled electric generator for wireless wearable electronics

Abstract

Environmental moisture, a ubiquitous and renewable resource, presents a promising avenue for green and sustainable power generation. Current moisture-enabled electric generators (MEGs) often exhibit low per-unit current output. Our study introduces a high-current, bendable, and tunable MEG. At 90% relative humidity, our MEG unit achieves a current density of 0.625 mA cm⁻², significantly surpassing previous MEGs by an order of magnitude. It also maintains 90% electric performance after one month, with a stable power output above 3 W m⁻². We have streamlined the fabrication process by directly coating a functional layer on flexible printed circuit boards (FPCB), enhancing the feasibility of industrial production. Furthermore, we demonstrate a low-power, wearable, wireless acceleration/strain monitoring system that operates exclusively on ambient humidity or human sweat with a reliable sampling frequency of 100 Hz. This device, with its simplicity, flexibility, electrical tunability, and superior current density, opens new avenues in sustainable energy, especially for wearable electronics.