Bending of polyelectrolyte membrane-platinum composite by electric stimuliIII: self-oscillation

Oscillatory bending responses of a solid polymer electrolyte membrane (SPM) -platinum (Pt) composite synchronized with anodic potential oscillations un der galvanostatic conditions were determined. The oscillations took place w hen the anodic oxidations of formaldehyde or sodium formate in aqueous :sul furic acid solutions were carried out on a plated Pt electrode. The frequen cy and the waveform of the: oscillations depended on the concentration of t he organic compounds and the direct current applied. The phenomena are disc ussed in the light of a previously published model in which we proposed tha t the interfacial stress between the membrane and the electrolyte causes th e bending response. (C) 2000 Elsevier Science Ltd. All rights reserved.