Electromechanical stability of buckled thin metal films on elastomer

Oxidizable metals such as Al are found to become highly resistive when exposed to air in buckled state, > 10× resistance increase compared to that in flat configuration. On the other hand, noble metal and oxide conductor films, such as Au and indium tin oxide show negligible resistance increase. The enhanced oxidation of grain boundaries that are exposed to air when buckled is found to be responsible for the observed electromechanical stability. Simple yet effective method, i.e., thin capping layer of noble metal, to prevent the oxidation of non-noble metal is proposed and experimentally verified.