Contact electrification behaviors of micro-patterned polydimethylsiloxane

We have investigated the contact electrification mechanism of identical materials using micro-patterned polydimethylsiloxane (PDMS) polymers. Commercially available sandpapers with various grit sizes were used for systematic control of the micro-patterns. Microstructure and hardness measurements revealed that the micro-patterns of sandpaper were successfully transferred to PDMS without significant change of the Young’s modulus. Clear triboelectric outputs were observed when contact separation was performed for identical PDMS polymers. The triboelectric outputs were significant when the microstructure was different, while the outputs were small when the microstructure was similar. These results were explained by the bond-breaking and ion/material transfer due to the roughness-induced temperature differences in identical PDMS polymers.