Sustainable and flexible hydrovoltaic power generator for wearable sensing electronics

Along with the development of flexible electronics, there is a pressing demand for a suitable power supply featuring great flexibility, high mobility, good stability, and sustainability. Converting thermal energy into electricity during water evaporation process could be an attractive and promising opportunity. Here, a sustainable flexible hydrovoltaic power generator (HPG) driven by water evaporation with high performance in portability, flexibility, and long-term stable electricity generation was developed. Based on constructed functionalized nanochannels and the introduction of superabsorbent hydrogel as a water source, the HPG can take advantage of the spontaneous evaporation of water to continuously convert ambient heat into electricity. A sustainable short circuit current up to 63 μA and an optimized output power of 8.1 μW with a lifetime over 150 h were achieved at ambient conditions (20.4 °C, 55% RH). Moreover, the flexible hydrovoltaic nanogenerator can withstand a large range of bending deformation (up to 120°) without significant changes in power generation, which endows evaporation-induced HPGs with the ability to be applied as flexible portable power sources for wearable electronics.