https://www.scientificamerican.com/article/cool-butterfly-effect-insect-equipment-could-inspire-heat-radiating-tech/

Devising better cooling materials has become a pressing issue as the climate warms, and some scientists are turning to nature for ideas. Small creatures with low body mass, such as insects, have to deal with the fact that they warm up much faster than large mammals. When butterflies land on tree branches to bask in the sun, for example, their relatively large wings can overheat within seconds. So they have evolved sophisticated ways to cool themselves. Researchers at Columbia University and Harvard University have now uncovered these colorful insects’ built-in cooling mechanisms. Their wings behave a bit like nanoscale radiators and could inspire new lightweight materials to beat the heat.

Heat is electromagnetic radiation generated by the vibration of molecules, explains study co-author Nanfang Yu, an associate professor of applied physics at Columbia’s Fu Foundation School of Engineering and Applied Science. The more molecules a material can expose on its surface, the more heat it can dissipate in a process called radiative cooling. So depending on their structure, some materials can release heat more quickly than others. Those made of corrugated layers shaped like waves, pleats or cylindrical tubes, for example, cool off much faster than solid objects because they have more exposed surface area. This observation is why home radiators are usually constructed to run heat through numerous metal folds, which efficiently release warmth into a room.