We are continuously developing new sub-micron sized and very high resolution sensors, to improve the measurements of near field heat transfer and quantized thermal conduction. The principle of operation of our sensors is currently based on the thermo-electrical effect (Seebeck Effect).

If a metal is heated at one end, electrons (on average) move from the hot to the cold end due to diffusion processes. The accumulating electrons build up an opposing electric field, which reduces the thermal diffusion current to zero at a material-dependent voltage (related to the Seebeck coefficient). Connecting two metals with different Seebeck coefficients at one end and keeping the temperature at the "loose ends" at a constant value allows for the measurement of the relative voltage difference between the two electric fields when a temperature change is applied to the connected end(s) of the metals. This voltage difference is what we refer to as a thermo-voltage. Through special preparation techniques, such a thermocouple is embedded in a scanning tunneling microscope tip and allows for the simultaneous measurement of heat transfer (by thermo-voltage) and the sample topography (via tunneling current)