Silver hairs keep Saharan Silver Ants cool
Gold and silver remain always precious for mankind. Saharan silver ants are adding a new chapter in evolution by using silver to remain cool. This ant lives in the desert where the surface temperature reaches to 70°C, far beyond 53.6°C, critical temperature to survive. Norman Nan Shi and his team from Columbia University, Brookhaven National Laboratory, University of Washington, USA and University of Zürich, Switzerland found that the secret of silver ant to survive in hot desert is silvery hairs. They found that the ants have dense array of uniquely shaped triangular hairs with two different thermoregulatory effects. They enhance not only the reflectivity of the ant’s body surface in the visible and near-infrared range of the spectrum, where solar radiation culminates, but also the emissivity of the ant in the mid-infrared. The latter effect enables the animals to efficiently dissipate heat back to the surroundings via blackbody radiation under full daylight conditions. This biological solution for a thermoregulatory problem may lead to the development of biomimetic coatings for passive radiative cooling of objects.