Researchers from a Canadian university and Corning have successfully implanted transparent sensors into the Gorilla Glass used by most smartphones, possibly allowing a future where touchscreens are also sensory devices.
Instead of using electricity, however, the two transparent devices—one a conventional temperature sensor, the other a more novel way of authenticating a smartphone—use optical waveguides, funneling photons through glass channels rather than electricity through wires.
Raman Kashyap, a professor of electrical engineering at the Polytechnique Montreal in Canada, said it should be possible for manufacturers to begin building in the technology inside of smartphones within a year with “focused development.” “We are actively looking to partner with industry to exploit this technology,” Kashyap says.
Each sensor was laser-etched into the glass itself, the first time photonics have been embedded into the rugged, scratch-resistant Gorilla Glass, according to a paper published by Optics InfoBase. In fact, the researchers claimed that Gorilla Glass yielded the lowest-measured loss value, the fastest fabrication times, and the longest, high-quality waveguides of any glass. The waveguides used by the researchers took 10 seconds to write on average, they said.
The temperature sensor was known as a Mach-Zehnder interferometer (MZI) based temperature sensor, which uses the way in which glass deforms under heat to deduce the temperature as light passes through the waveguide. The researchers also etched a unique waveguide into the screen, allowing it to uniquely identify itself when infrared light shone through it. In the latter case, the researchers said, the optical waveguide could be used to ensure the phone wasn’t cloned.
Kashyap said that the development of the transparent sensors anticipate a future where sensors could be embedded into any glass surface. So far, in addition to the waveguide temperature sensor developed by his team, a force sensor has been developed through an independent research effort. Since the waveguides are etched by laser in three dimensions, they can even be stacked over one another—again, without a loss in transparency.
Though the team included Ming-Jun Li, a researcher at Corning, the company has made no announcements about embedding waveguides into future glass. Corning has already moved on to its third generation of strengthened Gorilla Glass, as well as an anti-microbial effort. But there’s always hope for the future.