Scanning triboelectric nanogenerator as a nanoscale probe for measuring local surface charge density on a dielectric film

Applied Physics Letters, Volume 118, Issue 19, May 2021. Inspired by the contact-separation mode triboelectric nanogenerator (TENG), we propose a technique for local surface charge density measurement based on atomic force microscopy. It is named as scanning TENG, in which a conductive tip tapping above a charged dielectric surface produces an AC between the tip and the dielectric bottom electrode due to electrostatic induction. The Fourier analysis shows that the amplitude of the first harmonic of the AC is linearly related to surface charge density. The results demonstrate that the scanning TENG is a powerful tool for probing nanoscale charge transfer in contact-electrification.