An integrally underwater self-healable droplet-based triboelectric nanogenerator

Abstract

In recent years, droplet-based triboelectric nanogenerators (TENGs) have triggered intense research interest as self-powered devices due to their capability to harvest energy from water droplets efficiently. To make droplet-based TENGs less harmful to the environment and recover the output performance in time after being damaged, it is very necessary to fabricate an underwater self-healable TENG that is free from contaminating spills. In this work, via adding an environmentally friendly plasticizer to activate dipole–dipole interactions between polymer chains, which are employed as the driving force for self-healing, an underwater self-healable material is successfully developed, based on which an integrally self-healable droplet-based TENG (SHD-TENG) is fabricated. The device can produce an output voltage of 20 V and an output power density of 4.35 mW m⁻². After the entire device is damaged, the output voltage can recover 85% after being soaked in water for 12 h to self-heal, which is similar to healing in air. Moreover, a higher temperature can accelerate the healing of the device. This work presents an avenue to develop droplet-energy-harvesting electronics with underwater self-healing capability.