University team transforms any surface into touch interface

A team at Nanyang Technological University (NTU) has developed a low cost solution that can transform whiteboards, glass windows and wooden tabletops into responsive, touch sensitive surfaces. The solution uses vibration and imaging to track movements of multiple fingers and objects. Virtually any surface can be transformed into a touch surface so flat-panel displays can be cheaply retrofitted with the system.

Once hooked up to a computer, the modified TV screens can be used as interactive billboards, retail directories or digital whiteboards that can track what is drawn or written.

NTU Assistant Professor Andy Khong led the research. “Our innovative system is able to transform surfaces such as wooden tables, aluminium, steel, glass and even plastics into low-cost touch screens,” he said. “It means in future, you could play computer games or draw sketches on walls or windows since almost all surfaces can be made touch-sensitive with our system.”

The STATINA (Speech Touch and Acoustic Tangible Interfaces for Next-generation Applications) projector exploits the principles of vibration waves propagating on a solid surface.

By using a few low-cost vibration sensors and a specially developed algorithm, the system can pinpoint the location of a light tap on any surface. When further equipped with low-cost web-cameras, this system can also track the movements of multiple fingers or objects on any surface.

Since sound waves propagate through matter at a certain speed, it is possible to derive the location of the touch based on when each sensor picks up the signal, Professor Khong added.

His team are now working to commercialise the system by developing a more compact system and expanding its capabilities to include tracking of fingers and stylus movements using optical cameras.

So far, they have tested their system on surfaces such as wooden tables, aluminium, steel, glass and plastics.