Increasing the output signal from CPP GMR devices by increasing the read current has not previously been considered an option because it would make the device run too hot. This problem has been overcome by using, for the upper and lower leads, materials that differ significantly in their thermoelectric powers. Thus, when DC is passed through the device, from − to + TEP leads, hot and cold junctions are formed and heat is transferred from the micro-device into the leads, resulting in a net local cooling of the device which enables it to operate at higher power. For a GMR device, this translates to a larger output voltage, making it easier, more sensitive, and more reliable to use.