This letter presents the details of a novel battery architecture based on superhydrophobic nanostructured materials. Both electrodes of a battery are formed on nanostructured silicon surfaces that are subsequently treated to make them superhydrophobic, effectively separating the liquid electrolyte from the active electrode materials. When the battery is activated to provide power, a phenomenon called electrowetting promotes electrolyte penetration into the electrode space to initiate an electrochemical reaction. This architecture makes possible an extremely long shelf life, instantaneous ramp-up to full power, and chemistry-independent functionality. © 2005 Lucent Technologies Inc.