Self-powered TENG probe for scanning surface charge distribution

Abstract

Triboelectric nanogenerators are remarkable devices that show great potential in harvesting energy from mechanical work and are generally used for sensing purposes. Here we report a novel method for the fabrication of ZnO microspheres and the formation of TENG based on ZnO/PDMS composite. The zinc oxide microspheres with needle decorated structure via thermal oxidation of metallic zinc was grown at 500 °C. The TENG was then fabricated using ZnO/PDMS composite with Au sputtered electrode. While PDMS is a good triboelectric material, its output power density is low. Embedding ZnO micro/nanostructures in PDMS increases the output power of PDMS-based TENG manifolds. ZnO with a high dielectric constant exhibits semiconductor properties as well as piezoelectric properties. This combines with the triboelectric properties of PDMS and gives a significant boost to the TENG performance. This composite structure is used for the fabrication of high output power density TENG using contact separation mode, where the power density of 27Wm−2 was achieved. Consequently, a novel device application to detect surface charge density through the fabricated TENG is reported and the subsequent reconstruction of surface charge topology based on the detected surface charge density on large surfaces is presented. This technique may be used for the study of surface charge morphology, electrostatics, triboelectric constants, and various other material properties for characterization and application purposes.