High-output moisture-enabled electricity generator for fully self-powered wearable physical and biochemical monitoring

Spontaneous conversion of environmental moisture energy to high-output electricity can help meet the massive electricity demand of wearable electronics. However, low power density and inefficient energy harvesting are the main challenges to power electronics currently. Herein, we developed a flexible moisture-enabled electricity generation (MEG) membrane with high output power. The asymmetrical structure of the moisture-enabled flexible units is composed of a bilayer of polyanion and polycation. The single device produced a sustained voltage of 0.8 V and can be customized by an aligned stacking strategy for scale integration on demand. Enhanced by increasing the diffusion speed of carriers with the metal-air reaction, the output power reached 286.5 μW/cm2, which is enough for long-term wearable health monitoring. Meanwhile, to solve the power supply challenge of the wearables, a fully self-powered system with an energy harvester, a power management module, and a wireless and wearable sensing module was developed. Biochemical indicators and body motion were detected and monitored by the sensor array, demonstrating the promising application in wearable health management, including harvesting energy from giant moisture and powering wearable electronics.