Flexible e-skin for robots, prosthetics developed

Scientists have developed an ultrathin, stretchable electronic skin that could help robots and prosthetic devices to 'feel' and better interact with the environment and humans.

Human skin contains sensitive nerve cells that detect pressure, temperature and other sensations that allow tactile interactions with the environment. To help attain these abilities, scientists are trying to develop electronic skins.  

Researchers from University of Coimbra in Portugal and Carnegie Mellon University in the US wanted to develop a fast, simple and inexpensive method for producing thin-film circuits with integrated microelectronics. In the new approach, they patterned a circuit template onto a sheet of transfer tattoo paper with an ordinary desktop laser printer. They then coated the template with silver paste, which adhered only to the printed toner ink. 

On top of the silver paste, the team deposited a gallium-indium liquid metal alloy that increased the electrical conductivity and flexibility of the circuit. They added external electronics, such as microchips, with a conductive "glue" made of vertically aligned magnetic particles embedded in a polyvinyl alcohol gel. 

The researchers transferred the electronic tattoo to various objects and demonstrated several applications of the new method, such as controlling a robot prosthetic arm, monitoring human skeletal muscle activity and incorporating proximity sensors into a 3D model of a hand.