Heat-sensitive artificial skin mimics viper organ

The skin uses a mechanism similar to that of the pit organs in vipers, which allow the snakes to sense prey in the dark by detecting its heat. It was discovered when the team was fabricating synthetic wood in the lab, and created a material with an electrical response to temperature changes. The component responsible was found to be pectin.

"Pectin is widely used in the food industry as a jellifying agent; it's what you use to make jam. So it's easy to obtain and also very cheap," said research lead Chiara Daraio, professor of mechanical engineering and applied physics at Caltech’s Division of Engineering and Applied Science.

Using water and pectin, the team created a thin film just 20 micrometres thick. The pectin molecules have a weakly bonded double-strand structure that contains calcium ions. The bonds break down as temperature rises and the double strands ‘unzip’, releasing the positively charged calcium ions.