By Claire Bates
Skinput could solve the problem of ever shrinking gadget screens
Those who find the touchscreens on their ever shrinking gadgets too fiddly to handle, will be glad to hear scientists are developing a new touch surface... your own arm.
Developers at Microsoft Research and Carnegie Mellon University are working together to create an armband that projects an interface directly on to your skin.
They have combined a mini projector which creates a changing display with a sophisticated sensor that can tell which part of your arm is being tapped
A video showed how Skinput could recognise a telephone number being typed out on a hand
The researchers showed Skinput can be used to control audio devices, play simple games like Tetris, make phone calls and navigate simple browsing systems.
Lead researcher Chris Harrison from Carnegie Mellon University told the Mail Online: 'This is cutting edge technology and we really are seeing the future here.
'The project is going very well and I think you'll begin to see such interfaces emerge within the next five years.'
The gadget effectively turns your arm into a touchscreen surface by picking up various ultra-low sounds produced when you tap different areas.
Different skin locations are acoustically distinct because of bone density and the filtering effect from soft tissues and joints. The team then used software that matched sound frequencies to specific skin locations.
If the prototype isn't resting on the arm, it uses wireless technology like Bluetooth to transmit the commands to the device being controlled, such as a phone, iPod, or computer
Researchers said our skin is perfect as it is a display surface that we always take with us
Writing in a paper for Microsoft Research, Chris Harrison, Desney Tan and Dan Morris, said: 'Our skin has been overlooked as an input canvas and is one that happens to always travel with us.
'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.
'We can readily flick each of our fingers, touch the tip of our nose, and clap our hands together without visual assistance.'
The sensor picks up two two types of acoustic signals - transverse waves created by the rippling of skin as it's tapped and longitudinal waves that travel through the soft tissue of the arm and excite the bone.
The armband prototype can be combined with an MP3 player and used to change the song or volume level
Skinput will be presented at a computer conference in April
Currently, the acoustic detector can detect five skin locations with an accuracy of 95.5 per cent, which would be high enough for many smartphone applications.
Mr Harrison told the Mail Online: 'We achieved high input accuracy in the lab with about one error in 20 key presses, which is similar to what you might find on an iPhone keyboard.'
Twenty volunteers who have tested the system said they found it easy to navigate.
The researchers added that Skinput also works well when the user is walking or running.
There are many potential markets for the device. Mr Harrison said: 'One example is an audio player on your upper arm. Perhaps it has no buttons at all, and only uses the skin as the finger input canvas.
'You could then just tap your fingers to advance to the next song, change the volume, or pause the current song. You wouldn't even need a projector for most of these types of interactions.'
The researchers plan to present their work in April at the Computer-Human Interaction meeting in Atlanta, Georgia.