Turn your arm into a touch screen

The right hand clung to the left forearm, both trembling slightly, she was trying to suppress her anxiety? While patting the forehead, he was trying to remember a name? - No, they are using mobile phones and laptops.

US researchers have developed an interface based on human skin, turning human bodies into mobile phones, music players, personal computers . into touch screens.

The trick is in sound

The Skinput system developed by Carnegie Mellon University researchers and Microsoft is the "bond" of two technologies: the ability to detect ultra-low frequency sounds emitted by tapping fingers lightly on the skin and mini projectors (microchip-sized) are available in some mobile phones.

This system projects the keyboard or menu on the forearm and hands from a projector placed on the armband at the upper arm. An audio detection device also placed on the armband is responsible for calculating whether the user wants to activate the part of the display.

How does Skinput recognize user icons, buttons or fingers tapping on his skin?

The arm becomes a touch screen.Photo: ACM

Chris Harrison (Carnegie Mellon University), Dan Morris and Desney Tan (Microsoft Research Department) exploited how skin, muscle and skeletal systems work together to create distinctive sounds when people tap on parts. Different of arms, palms, fingers .

The researchers identified many positions on the forearm and the hand emitted characteristic sounds when tapping the finger.

The audio detection device located in the armband consists of 5 piezoelectric layers which is responsible for responding to certain sound frequencies. Sensors are linked together on multiple levels, depending on the position on the arm being knocked on.

Recently, 20 volunteers tested Skinput and mostly interacted with symbols on the forearm easily. They freely tapped their fingers, flicking their fingers to execute the device control command. The system works well with a variety of gestures and gestures, even when the user is on the move.

Some people use their forefinger to tap on the shining computer projection shown on the palm to make addition, subtraction, multiplication and division calculations. Some people snapped their fingers, the music listening menu ran up and down on the forearm. Someone just walked up and spread his palms and displayed a Tetris game that patted his forearm to play a classic brick game .

Open up many applications

Skinput can use wireless technology like Bluetooth to transfer control commands to a variety of devices, including phones, iPods and personal computers.

The researchers will present their work at the ACM Human-Computer Interaction Conference held in Georgia (USA) in April.

Pranav Mistry, who works at the Massachusetts Institute of Technology's Media Laboratory, notes that users must wear their armbands carefully so that the projection always appears in place.

Michael Liebschner, Director of the Biological Improvement Laboratory of Baylor College of Medicine (USA), said that Skinput has a wide range of applications in life. He has studied bone-based sound transmission technology to transmit signals between devices.

'Using the body as an input device seems to be a very viable solution. While immersing yourself in a virtual game using a 3D monitor mounted on your head, you cannot remove it to touch the controls. Skinput makes things a lot easier, ' commented Liebschner.

If Skinput is commercialized, it may be necessary to redefine some common gestures. For example, tapping your fingers intermittently, nervousness might be texting, or patting the forehead as if trying to remember something means turning on the web browser .