A new prototype triboelectric nanogenerator with superhydrophobic and self-cleaning features is invented to harvest water drop energy based on a sequential contact electrification and electrostatic induction process. Because of the easy-fabrication, cost-effectiveness, and robust properties, the developed triboelectric nanogenerator expands the potential applications to harvesting energy from household wastewater and raindrops.

Electrical wave mechanics: A newly designed triboelectric nanogenerator is based on the contact electrification between a patterned polydimethylsiloxane pyramid array and water. Cost‐effective and simple, the prototype triboelectric nanogenerator shows the potential to harvest energy from liquid waves and serve as chemical and temperature sensors.

When water is passing through the air or an insulating tube, it will contain not only the mechanical energy but also the electrostatic energy due to the existence of triboelectric charges on its surface as a result of contact with the air/solid surface. In this paper, a hybrid triboelectric nanogenerator (TENG) is designed to simultaneously harvest the electrostatic and mechanical energies of flowing water. Water-TENG, mainly constructed by a superhydrophobic TiO2 layer with hierarchical micro/nanostructures, is used to collect the electrostatic energy of water (Output 1). Contact-TENG, composed by a polytetrafluoroethylene film and a layer of assembled SiO2 nanoparticles, is used to collect the mechanical energy of water (Output 1 and Output 2). Using TiO2 nanomaterials in water-TENG provides the advantages of photocatalytic activity and antibacterial property for water purification. Under the impact of a water stream from a household faucet at a flowing rate of 40 mL s(-1), the generated short-circuit current from Output 1 and Output 2 of dual-mode TENG can reach 43 and 18 μA, respectively. The instantaneous output power densities from Output 1 and Output 2 of dual-mode TENG are 1.31 and 0.38 W m(-2), respectively, when connecting to a load resistor of 44 MΩ. The rectified outputs have been applied to drive light-emitting diodes and charge commercial capacitors. Besides, the water-TENG has also been demonstrated as a self-powered nanosensor for ethanol detection.