Mechanically flexible and optically transparent thin film solid state supercapacitors are fabricated by assembling nano-engineered carbon electrodes in porous templates. The electrodes have textured graphitic surface films with a morphology of interconnected arrays of complex shapes and porosity. The graphitic films act as both electrode and current collector, and when integrated with solid polymer electrolyte function as thin film supercapacitors. The nanostructured electrode morphology and conformal electrolyte packaging provide enough energy and power density for electronic devices in addition to possessing excellent mechanical flexibility and optical transparency.