Contact electrification studies using atomic force microscope techniques

Contact electrification measurements using atomic force microscopy techniques were performed using micrometer-sized spheres made of polystyrene and flat substrates of either freshly cleaved, highly oriented pyrolytic graphite (HOPG) or a 0.2-mu m-thick Au[lll] film grown on mica. The polystyrene/HQPG interaction exhibited significant electrostatic charging when compared to the polystyrene/Au system. This result is consistent with qualitative expectations of contact charging based on a triboelectric series of common materials. The observed contact electrification is also consistent: with electronic charge transfer between materials, rather than an ionic dr material transfer mechanism. (C) 1998 American Institute of Physics.