Self-powered VO 2 phase transition based on triboelectric nanogenerator

The metal–insulator transition (MIT) of vanadium dioxide (VO 2 ), which involves significant changes in electrical, optical, and other properties, has attracted widespread attention. Here, we report a triboelectric nanogenerator (TENG)-based self-powered VO 2 phase transition. With the TENG-induced ionic gel gating, the hydrogen ion insertion/detachment in the VO 2 lattice can be modulated at room temperature to cause phase transitions that control light transmittance. The phase transition behavior is characterized by X-ray diffraction and Raman spectroscopy. Under the continuous power supply from TENG, the X-ray diffraction peak of VO 2 shifts, and the Raman intensities of characteristic peaks decrease, accompanied by a color change from brown to translucent. The electrical conductivity undergoes a significant change by two orders of magnitude and persists overnight, indicating an excellent duration of the phase transition. In addition, a raindrop TENG-induced VO 2 phase transition is demonstrated. The infrared transmittance of VO 2 is decreased dramatically by 28.1% due to the phase transition, achieving a heat preservation effect that holds promise for adaptive thermal insulation in smart windows during rainfall through raindrop power generation. This work has realized the TENG-based self-powered VO 2 phase transition, holding significant application potential in smart homes.