If I started talking about epidermal electronics, you might well click away from this post because you think I'm going to blind you with science. But if I referred instead to electronic tattoos, you might be able to have a reasonable guess at what they are particularly if I tell you that they're used for medical purposes. Simply put, they're ultra-thin postage stamp-sized electronic systems that read the body's vital signs, replacing the sometimes uncomfortable rigid medical electrodes and monitors which are surgically glued to one's skin the ones which mean you have to shave in places you really didn't want to shave.
Not for much longer, though. At the University of Illinois, researchers have created a clever little piece of technology to read the body's vital signs and gather data by sticking these so-called electronic tattoos on to patients' skin in place of all those wires, electrodes and gizmos. Measuring just 37 micrometres (that's less than the thickness of a human hair), these pliable pieces of electronic wizardry offer a non-invasive and comfortable way to gather the data with the most minimal interference or inconvenience to the patient.
"The skin is a particularly interesting point of integration," says John A. Rogers, the materials science professor who led the team. "Skin is the largest organ. It provides our main point of non-visual sensory interaction with the outside world, and it is a place where people have attempted to interface electrodes and electronics for decades."
Given the above, it seems natural and almost surprisingly obvious, way to use technological advances (medical or otherwise) to try and use and work with the skin. Hence electronic tattoos. The components are made from silicon and gallium arsenide nano-membranes, formed into filaments with a malleable, snake-like shape. This makes them comfortable and able to mould to and move with the skin which is, of course, soft, pliable and relatively easily damaged. The filaments are then wired up, creating a "spider web mesh of electronics" that can move with the skin.
The components, which also contain solar cells to generate power or get energy from electromagnetic radiation, are applied to a flexible material and then mounted onto a backing sheet which keeps everything stiff enough to handle and so that it can be pressed directly on to the chosen area of skin but still keeping it thin enough to be comfortable for up to two weeks comfortable enough, in fact, to attach to premature babies to monitor their progress. And if the average wearer doesn't like looking at an electronic component stuck to their arm or wrist or wherever else, they can simply get a temporary tattoo, which actually doubles as the polymer backing sheet.
After two weeks, though, the tattoo would need to be replaced simply because the top layer of skin cells would have died and been brushed off by that point.
Clearly the implications for medical monitoring alone are very significant, doing away with wires, bulky equipment, and, crucially, enabling mobile monitoring (after all, monitoring someone in their natural environment rather than in a lab has to be better and more effective); but there is a recreational purpose for which such electronic tattoos could be used, too. I'm referring to the industry that's taken over the world gaming. What Rogers' team found was that when the tattoo was attached to the throat, it could recognise basic vocal commands: up, down, left, right. So it's not beyond the realms of possibility that voice-activated games could reach the gaming market in the not so distant future, when the vocabulary which the tattoos recognise expands.
It reminds me of the 1982 film Firefox with Clint Eastwood, where he had to think in Russian in order to activate the weapons of the supersonic fighter plane, giving him that split-second advantage over a dogfight opponent. There's no mention of using these electronic tattoos for military purposes, so I hope I haven't given anyone any ideas...