Control heat transfer between nanostructures through rotation

All hot bodies emit heat in the form of electromagnetic radiation, as occurs with incandescent filament light bulbs. Night vision cameras are another example of technology based on this physical phenomenon. Up to now experience has indicated that heat is always directed from hot bodies to cold bodies. A study has shown that this does not happen between two nanostructures if they are rotated. This finding could have an application in the generation of thermophotovoltaic energy or the thermal control of electronic devices.

“We have shown how, depending on their rotation frequencies, the radiative heat transfer between two rotating nanostructures can be increased, decreased or even reversed with respect to the transfer that occurs between nanostructures in the absence of rotation. This allows us to have a greater degree of control over radiative heat transfer,” says Juan Deop-Ruano, a researcher at the Institute of Optics (IO), attached to the Higher Council for Scientific Research (CSIC) in Spain, and co-author of the study.

Providing new ways to control radiative heat transfer at the nanoscale is essential to solve technological challenges related to heat dissipation and energy production. The production of thermophotovoltaic energy, for example, is based on transforming heat into electromagnetic radiation and transferring it to a photovoltaic cell to produce electricity. The control of radiative heat transfer means that the transformation of heat into electromagnetic radiation can be carried out very efficiently.

Advances in electronics have led to the size of the transistors used in microchips now being on the nanometer scale. A fundamental problem with these systems is that they are very difficult to cool. “Knowing how to regulate radiative heat transfer at the nanoscale provides mechanisms to extract this heat and, therefore, design efficient refrigeration technologies”, adds Alejandro Manjavacas, also a CSIC scientist at the IO.

Artist’s representation of radiative heat transfer between two rotating nanostructures. (Image: Institute of Optics)

The study is titled “Control of the Radiative Heat Transfer in a Pair of Rotating Nanostructures”. And it has been published in the academic journal Physical Review Letters. (Source: CSIC)