A system is disclosed for harvesting at least one of mechanical or thermal energy. The system may have a flexible substrate, a plurality of electrically conductive nanowires secured to the substrate, and a plurality of electrically conductive metal layers. The metal layers may be disposed on the substrate and spaced apart from one another along a length of the substrate. The metal layers may be in electrically conductive contact with various ones of the nanowires. At least two of the metal layers may be attachable to an external device. At least one of movement or flexing of the substrate produces an output voltage across the metal layers.