The invention is directed to the application of EMR to one or more elements for the purpose of generating a scent response in humans. In particular, a layer of iridium or an iridium compound, preferably metallic iridium or iridium oxide supported on TiO2, is provided on the anode to electrolyze available water and pass the majority of the current during a reversal of the fuel cell, thereby preventing damage to the MEA. Also, formation of the cores is followed by formation of shells having a composition gradient. The arm section is integrally provided with a first wall portion opposed through the support member to the engaging portion.