Research work from a collaboration between Microsoft and Carnegie Mellon University (USA) has resulted in an armband that can sense taps on human skin (the arm in this case) and uses sound vibration detection (an acoustic biosensor) to determine the location for a kind of crude ‘button’ or ‘keyboard’ arrangement. It also uses a picoprojector (like a tiny LED projector) to display the buttons on the skin. They call it skinput.
Obviously the advantage here is that nothing needs to be implanted under the skin to create an arm control panel. Of course, the external wristband is subject to the usual problems of a wristwatch – banging it against something, losing it, breaking the clasp. Although technology marches on, it can always use some tweaking.
Is anybody asking why ‘skinput’ is needed? (Be careful what you scorn – in a decade or two skinput might seem perfectly routine.)