Researchers unveil new way of interacting with gadgets

Chris Harrison, Skinput's creator, a PhD student in computer science at Carnegie Mellon and colleagues Desney Tan and Dan Morris from Microsoft Research, devised sensors on the arm to listen for input. Harrison told BBC News: "A tap with a finger on the skin scatters acoustic signals throughout the arm. Some waves travel along the skin surface and others propagate through the body. Even better the physiology of the arm makes it straightforward to work out where the skin was touched." According to Harrison, differences in bone density, arm mass as well as the 'filtering' effects that occur when sound waves travel through soft tissue and joints make many of the locations on the arm distinct. Software coupled with the sensors can be taught which sound means which location. Different functions, start, stop, louder, softer, can be bound to different locations. The system can even be used to pick up subtle movements such as a pinch or muscle twitch. Harrison continued: "Appropriating the human body as an input device is appealing not only because we have roughly two square meters of external surface area, but also because much of it is easily accessible by our hands (e.g., arms, upper legs, torso). "Furthermore, proprioception (our sense of how our body is configured in three-dimensional space) allows us to accurately interact with our bodies in an eyes-free manner. For example, we can readily flick each of our fingers, touch the tip of our nose, and clap our hands together without visual assistance. Few external input devices can claim this accurate, eyes-free input characteristic and provide such a large interaction area."