A bio-inspired total current nanogenerator†

Abstract

Conventional nanogenerators typically employ displacement current as the driving force to output alternating current (AC). It is thus inevitable to face a series of complex power management issues, such as AC–DC conversion and AC phase asynchrony, leading to a bulky, inefficient and costly energy harvesting system. Here, inspired by the electricity generation mechanism of electric rays, a high-performance droplet-based nanogenerator on the basis of solid–liquid contact electrification is developed, which employs both displacement current and conduction current as the driving forces to output high-voltage direct current (DC) without a rectifier. This new device, defined as a total current nanogenerator, has the characteristics of compact array architecture, high-voltage DC output, and controllable energy release, successfully realizing the voltage-controlled electric shock process. Since the output voltage of the developed nanogenerator is as high as 3000 V, a single discharge is sufficient to light up more than 1260 LEDs, demonstrating its unparalleled capability for harvesting high-entropy water energy. The total current nanogenerator proposed in this work provides new insights into the theory and technology of energy harvesting from solid–liquid interfaces.