Thinking that the tiny touchscreens on today’s mobile devices are not so comfortable to use, Chris Harrison from Carnegie Mellon University in collaboration with Dan Morris and Desney Tan from Microsoft research lab in Redmond, Washington have developed a new technology that uses the human body as touchscreens. Called Skinput, it is based on detection of ultralow-frequency sounds produced when different part of our skin is tapped.

    As you see in the video clip below, Skinput beams a keyboard, menu or other graphics onto user’s forearm and palm, from an armband projector. An acoustic detector, situated also on the armband, calculates which part of the display was activated by the user’s touch. But how does the system knows which button we tapped? The researchers reveal to us that different bones density, their size and mass determine distinctive sounds when we tap on different parts of our body.

    Currently, the acoustic detector seams to detect five skin location with an accuracy of 95.5%. Then, the system uses Bluetooth technology to transmit the command to the devices that you control: a cell phone, an iPod, MP3 player or a computer. The twenty volunteers which have tested the new “touchscreen” found it is easy to navigate through icons on the forearm and finger taps and found out that Skinput also works well when walking or running.

    So, it seams that in future we’ll get rid of using the uncomfortable tiny touchscreens of our pocket-size gadgets. The researchers noted that the human body is tempting to use it as an input device “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).”

    Skinput: body is the ultimate limit of touch

    Skinput: body is the ultimate limit of touch

    “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,” the researchers wrote in a recent paper. “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.”