Human skin contains sensitive nerve cells that detect pressure, temperature, and other sensations that allow tactile interactions with the environment. To help robots and prosthetic devices achieve these abilities, scientists are trying to develop electronic skins. Now researchers are reporting a new method in ACS application materials and interfaces which creates an ultra-thin, stretchable electronic skin that can be used for various human-machine interactions.
Electronic skin can be used for many applications, including prosthetic devices, wearable health monitors, robotics, and virtual reality. The main problem is the transfer of ultra-thin electrical circuits to complex 3D surfaces, and then with the possibility of flexibility and stretching of the electronics to provide movement. Some scientists have developed flexible "electronic tattoos" for this, but their production is usually slow, expensive, and requires clean room techniques such as photolithography. Mahmud Tavakoli, Carmel Madjidi and his colleagues wanted to develop a fast, simple and inexpensive method for producing thin-film circuits with embedded microelectronics.
In the new approach, the researchers created a pattern of the scheme on a sheet of a portable tattoo with a conventional desktop laser printer. They then coated the template with silver paste, which stuck only to printed toner inks. At the top of the silver paste, the team laid siege to an alloy of liquid gallium-indium metal, which increased the electrical conductivity and flexibility of the circuit. Finally, they added external electronics, such as microchips, with a conductive “glue” of vertically aligned magnetic particles embedded in a gel of polyvinyl alcohol. The researchers transferred the electronic tattoo to various objects and demonstrated several applications of the new method, such as controlling the prosthetic arm of the robot, monitoring the activity of human skeletal muscles, and including proximity sensors in the three-dimensional model of the arm.
Materials provided by American Chemical Society, Note. Content can be edited for style and length.