TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The membrane includes multiple layers of material. The n-type semiconductors extend into an anode layer of the membrane and the p-type semiconductors extend into a cathode layer of the membrane. The membrane includes an intermediate layer between the anode layer and the cathode layer. The intermediate layer is more electrically conducting than the cathode layer, and the intermediate layer is more electrically conducting than the anode layer. The n-type semiconductors physically contact the intermediate layer, and the p-type semiconductors physically contact the intermediate layer. The n-type semiconductors extend through the anode layer, and the p-type semiconductors extend through the cathode layer. A ratio of a thickness of the anode layer:a thickness of the intermediate layer is greater than 5:1 and a thickness of the cathode layer:a thickness of the intermediate layer is greater than 5:1. The intermediate layer includes one or more ionomers. The n-type semiconductors have an average length:width ratio greater than 5:1, and the p-type semiconductors have an average length:width ratio greater than 5:1. The n-type semiconductors extend into an anode layer of the membrane, the anode layer includes a cationically conductive ionomer. A bandgap of the n-type semiconductors is larger than a bandgap of the p-type semiconductors. The p-type semiconductors include p-type silicon, the n-type semiconductors include a metal oxide, and the membrane is ionically conducting while being impermeable to hydrogen and oxygen, and optically transparent. A portion of a length of each n-type semiconductor is embedded in the membrane while a remaining portion of the length of each n-type semiconductor is located outside of the membrane and an average percentage of the n-type semiconductor length embedded in the membrane is greater than 10%, and a portion of a length of each p-type semiconductor is embedded in the membrane while a remaining portion of the length of each p-type semiconductor is located out side of the membrane and an average percentage of the p-type semiconductor length embedded in the membrane is greater than 10%.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The ionomers includes poly(3,4-ethylenedioxythiophene): poly (styrenesulfonate). The ionomer is copolymers of a substituted or unsubstituted alkylene and a sulfonic acid. The p-type semiconductors extend into a cathode layer of the membrane, the cathode layer includes an ionomer. The ionomer is an anionically conductive poly(arylene ether sulfone). The poly(arylene ether sulfone) has a structure of formula (II).