A device includes a first thermally conductive substrate having a first patterned electrode disposed thereon and a second thermally conductive substrate having a second patterned electrode disposed thereon, wherein the first and second thermally conductive substrates are arranged such that the first and second patterned electrodes are adjacent to one another. The device includes a plurality of nanowires disposed between the first and second patterned electrodes, wherein the plurality of nanowires is formed of a thermoelectric material. The device also includes a joining material disposed between the plurality of nanowires and at least one of the first and second patterned electrodes.