Culminating four years of research, a team at Singapore's Nanyang Technological University has developed a technology that can turn a multitude of surfaces including wood, glass, aluminium, steel and even plastics into a low-cost multi-touch screen. The technology, named STATINA (for Speech Touch and Acoustic Tangible Interfaces for Next-generation Applications), is only a couple years away from reaching mass production.
STATINA uses low-cost vibration sensors and webcams to figure out the location of the initial point of impact of the user's finger, thanks to an ad-hoc algorithm that was developed to precisely triangulate the sensor data. When low-cost webcams are added to the setup, the system can continuously track the movements of multiple fingers or objects on the surface.
"The technology relies on the rigidity of the surface, and the system would work on most rigid surfaces such as wood, aluminum, glass, acrylic with minimal calibration – these have all been tested in our lab," Prof. Andy Khong, who led the research, tells Gizmag. "Based on the vibration sensors alone, the system will not work on cemented walls as the vibration signals attenuate too much. Our camera-based solution will come in handy for that."
Based on the vibration sensors alone, the system in its current state can achieve an accuracy of approximately 1.5 cm (0.6 in). "We also have another algorithm based on vibration sensing that has shown to achieve 0.5 cm accuracy, while our camera based technology can achieve accuracy of a couple of millimeters," says Khong.
The number of sensors needed depends on the size of the surface. An area equivalent to a 50-inch screen, for instance, would require 12 vibration sensors and two to three low-cost webcams.
To start with, the system could be retrofitted onto existing flat-panel TVs and then hooked up to a computer to be used as an interactive billboard or a digital whiteboard that can track what is being written. But this technology could be used for much more than that – it could turn virtually any flat surface into a workspace or an interactive gaming screen for a very low price tag.
Khong tells us that his team is now working on creating a more compact system and improving response time. He believes that the system might be able to reach mass production in about two years' time.
Papers explaining the technology behind STATINA were recently published in the journal IEEE Explore.