The Sahara silver ant survives ground temperatures of up to 70°C thanks to special triangular chitin hairs: These reflect solar radiation in the visible and near-infrared range while simultaneously releasing heat in the mid-infrared range (8–13 μm) almost unimpeded into space.

Ille C. Gebeshuber and Markus Zimmerl from the Institute of Applied Physics at TU Wien (Biomimetics) demonstrate in their new publication in “Physik in unserer Zeit” (German only), opens an external URL in a new window how this principle of passive radiative cooling can be made technically usable. The researchers are developing micro- and nanostructured surfaces based on chitosan, a biodegradable material derived from chitin. Such bionic cooling films could in the future cool buildings and facades in hot regions without energy consumption while being fully integrated into material cycles. The work impressively demonstrates how physical principles from nature can lead to resource-conserving technological solutions – entirely without active components or climate-damaging refrigerants.