An energy conversion device for conversion of various energy forms into electricity. The energy forms may be chemical, photovoltaic or thermal gradients. The energy conversion device has a first and second electrode. A substrate is present that has a porous semiconductor or dielectric layer placed thereover. The substrate itself can be planar, two-dimensional, or three-dimensional, and possess internal and external surfaces. These substrates may be rigid, flexible and/or foldable. The porous semiconductor or dielectric layer can be a nano-engineered structure. A porous conductor material is placed on at least a portion of the porous semiconductor or dielectric layer such that at least some of the porous conductor material enters the nano-engineered structure of the porous semiconductor or dielectric layer, thereby forming an intertwining region.