Effect of humidity and pressure on the triboelectric nanogenerator

Triboelectric nanogenerator (TENG) as a novel energy harvester has raised wide research interests recently, although the environmental effect on its performance is still lacking. This paper attempted to experimentally quantify the effect of the relative humidity (RH) as well as the pressure on the charge generated from a TENG. It was found that under the same mechanical excitation, the generated charge of the TENG increased more than 20% when RH decreased from 90% to 10% at the ambient pressure. However, the generated charge decreased as the air pressure decreased from atmospheric pressure to 50 Torr at RH close to 0%, while the optimal pressure shifted to a lower level when the relative humidity was higher. This study can contribute not only to the design and packaging of triboelectric devices to operate in varying environments and extreme conditions, but also to the fundamental understanding of the mechanism of triboelectric effect. (C) 2013 Elsevier Ltd. All rights reserved.