Water-bridge-assisted ionic conduction in probe-induced conical polymer pattern formation

Abstract

Water-assisted ion conduction in the formation of conical structures induced by the atomic force microscopy (AFM) probe on polymethyl methacrylates (PMMA) was analyzed. Water-assisted ion drift was found to be the predominant conduction mechanism for structure formation. The high current arising from water ionization provided effective Joule heating for polymer softening/melting. The results show that neither PMMA dissociation nor dielectric breakdown is involved in the conduction process.