Emerging design principles, materials, and applications for moisture-enabled electric generation

Smart generators that collect energy from the ambient environment are a new approach for meeting growing global energy needs. Moisture is one of the most abundant resources in the ambient environment, and using it to generate electricity has aroused great interest in recent years. In this review, we first summarize the emerging design principles of moisture power generation, including ion diffusion, streaming potential, and charged surface potential. Then, based on these fundamental principles, we systematically summarize the materials thus far known to be suitable for moisture power generation. Finally, we highlight the application of moisture energy generators in various fields, such as thermoelectricity, solar thermal evaporation, capacitors, strain sensors, and information storage, and discuss current challenges and future prospects for the development of moisture energy generators.