Biomimicking pit vipers' infrared sensing

Animals have evolved specialized tissues to sense temperature. Pit vipers have the most evolutionary advanced membranes that are used as infrared sensors to detect prey and predators at night. These membranes acquire their extraordinary sensitivity through voltage-gated ion channels of the wasabi heat receptor. So far, no engineered material with similar infrared sensitivity has been reported. Here we show that pectin films mimic the sensing mechanism and parallel the performance of the snakes' pit membranes. Pectin films react to distant infrared sources and can be used to map the temperature of surfaces. The films dramatically boost sensing capabilities in synthetic skins and can be exploited, for example, in robotics to sense proximity of humans or animals.