A customized kinetic energy harvesting system with multilayer piezoelectric membrane for solar interfacial vapor generation

Water evaporation is a highly energy-intensive phase change process due to the dynamically changing hydrogen bonding network with high energy density in liquid water. The hydrophilic polymer network in the hydrogel as well as the polarization and Lorentz force in an applied electric field can disrupt such a hydrogen bonding network, reducing the energy requirement for water evaporation. However, the limited activation region of hydrogels and the high equipment cost associated with external electric field severely trammel their practical application. Herein, multilayer piezoelectric fiber membranes are custom-arranged in a highly hydrated hydrogel for synergistic water activation. The customized piezoelectric functional layer can efficiently convert wave energy into electrical energy, activating the hydrogel to attain a high evaporation rate. The activation effect leads to an additional 28% enhancement compared to non-piezoelectric hydrogel evaporator. Additionally, accurate model building and computer simulation analysis expand the customization of functional layers to real marine environments.