Smart clothsNew tech could turn clothes into touch sensors

Everything from clothes and headphone wires to coffee tables could soon become interactive touch devices thanks to the development of new sensor technology.

Researchers at the University of Munich and the Hasso Plattner Institute are working to integrate technology originally designed to detect damaged underwater cables into touch sensors that can be installed in virtually anything.

Using time domain reflectometry (TDR), which has been used to detect damage in underwater cables by sending a short electrical pulse down a cable and waiting for the reflected pulse returns, researchers have been able to detect the location of an object.

According to Patrick Baudisch, professor of computer science at the Hasso Plattner Institute, engineers in the 1960s used TDR to locate when a wire had been touched. Over time the technology has become increasingly more accurate, making it possible to apply in interactive applications.

Raphael Wimmer, a University of Munich student and a member of Baudisch’s team, said implementing TDR in other materials was a fairly straightforward process.

To demonstrate the technology, Wimmer taped two parallel strips of copper to a piece of paper and proceeded to send second-long electrical pulses to the wires. When a finger touched the paper, the pulses would be reflected back and computer software would then be able to determine the location of the touch.

Wimmer is currently at work on shrinking the technology down to the size of a chip, as the current setup is still too bulky to be implemented more broadly. But Wimmer believes TDR can be used to create more effective touch screens as it only requires two wires whereas existing touch screens require a matrix of wires that line both sides of a screen.

“You have to route them to a controller in special ways, and that’s quite complicated,” he explained.

Jeff Han, the founder and CEO of Perceptive Pixel, a company that develops large multi-touch displays, is also optimistic about the potential of TDR technology.

“Wimmer’s application of TDR to touch is very clever,” Han said.

Han believes that it could eventually lead to novel methods to detect user input like sensing touch along an unmodified headphone wire.