Hydrovoltaic Materials and Devices: From Synthetic Materials, Macroscopic Biomaterials, to Micro Biomaterials

Much progress has been made in hydrovoltaic materials and devices. However, the power conversion efficiency of hydrovoltaic devices is still low. One of the main factors that determine the efficiency is the properties of hydrovoltaic materials. Herein, the research status of hydrovoltaic materials is summarized from the perspectives of synthetic materials, macroscopic biomaterials, and micro biomaterials, as well as the hydrovoltaic devices based on these materials. The development of materials is critical to improve the performance of hydrovoltaic devices. Various hydrovoltaic materials such as carbon nanomaterials, semiconductor nanomaterials, organic compounds, wood, paper, biomimetic materials, Geobacter Sulfurreducens, and milk are introduced, which involve from synthetic materials to macroscopic biomaterials and micro biomaterials.