'Electronic Skin' Grafts Gadgets to Body
He may have had a laser in his watch and a radio in his lighter, but even James Bond didn't sport gadgets tattooed to his skin. Now he could, thanks to the development of ultrathin electronics that can be placed on the skin as easily as a temporary tattoo. The researchers hope the new devices will pave the way for sensors that monitor heart and brain activity without bulky equipment, or perhaps computers that operate via the subtlest voice commands or body movement.
Stretchy and bendy electronics have been around for a few years. One approach is to write circuits onto materials that are already flexible, such as ink on paper, so gadgets can be folded and put away. Another is to make the circuits themselves flexible. In 2008, for example, engineers at the University of Tokyo created a conductive material that looked a bit like a fishnet stocking. Made of carbon nanotubes and rubber, it could stretch by more than a third of its natural length, possibly enough to make robots become more agile.
The problem with these past attempts, says materials scientist John Rogers of the University of Illinois, Urbana-Champaign, is that none of them has been as stretchy and as bendy as human skin. That's a shame, because scientists have had grand visions for integrating the skin with electronics, from medical sensors to music players or cell phones that you can literally wear on your arm.
ow, Rogers and his colleagues at Urbana-Champaign and other institutions in the United States, Singapore, and China have come up with a form of electronics that almost precisely matches skin's mechanical properties. Known as epidermal electronics, they can be applied in a similar way to a temporary tattoo: you simply place it on your skin and rub it on with water (see video). The devices can even be hidden under actual temporary tattoos to keep the electronics concealed.
Image credit: John A. Rogers