Abstract: A thermopile sensor including a uniform substrate having a first surface with a first section and a second section at an elevation varying relative to the first section by between about 5 micrometers and about 500 micrometers. The sensor further includes a plurality of thermopile junctions, with each junction having (i) a first strip of a first conductive material, extending from the first section to the second section, (ii) a second strip of a second conductive material, forming an electrical junction with the first strip on the second section and extending to the first section, and (iii) with the thermopile junctions being connected in series. A first contact pad on the substrate is connected to an initial thermopile junction and a second contact pad on the substrate is connected to a last thermopile junction, with conductors connecting to the first and second contact pads and extending off of the substrate.