14 DAY TRIAL // European researchers have recently developed a series of acoustic sensors that turn any surface into a touch-sensitive computer interface. Though the idea itself is quite new, the manufacturing process is rather simple. Two or more sensors are attached around the edges of the surface. These pinpoint the position of the finger, or of a touching object, by tracking vibrations. This allows them to create a virtual touchpad, or keyboard, on any 2d surface such as a wall or a table. The system is called Tai-Chi (Tangible Acoustic Interfaces for Computer-Human Interaction) and it was developed by researchers from Switzerland, Italy, Germany, France and the UK.
"We have made a system that can give any object, even a 3D one, a sense of touch. One advantage of the system is that for little cost you can have a much larger touch-sensitive area. The whole surface of your desk could become your keyboard and mouse-pad," claims Ming Yang, an engineer at Cardiff University, UK.
Tai-Chi uses tiny piezoelectric sensors to sense surface vibrations. The sensors are connected to a desktop computer loaded with software developed by the team and the resulting system can track a maximum of 2 objects moving independently in 2 different modes.
The first method measures differences in the amount of time it takes one particular vibration to reach 2 or 3 sensors. Using this sonar-like method any surface can be made touch sensitive simply by attaching the needed sensors. The other method is more accurate because it uses only one sensor that tracks the movement but also the pressure applied at one point and compares it to several measures located in a database. This method however is harder to apply since it requires pre-calibration of each sensor.
The results of such experiments could be limitless. Imagine how desk-integrated keyboards and touchpads could work in a germ-free environment such as a hospital or a medical center. The new products might prevail in front of the classic ones but it will take some time to get used to a touch-sensitive keyboard, especially if you like the feedback provided by a classic one.