Flexible Sensor Holds Potential for Foldable Touchscreens

The development of bendable, stretchable and transparent touch sensors is an emerging technological goal in a variety of fields, including electronic skin, wearables and flexible handheld devices. A new, inexpensive sensor developed at the University of British Columbia (UBC) could help make advanced devices like these a reality.

A close-up of the flexible sensor. Courtesy of the University of British Columbia.

The sensor uses a highly conductive gel sandwiched between layers of silicone that can detect different types of touch, including swiping and tapping; it can do so even when it is stretched, folded or bent.

"There are sensors that can detect pressure, such as the iPhone's 3D Touch, and some that can detect a hovering finger, like Samsung's AirView. There are also sensors that are foldable, transparent and stretchable,” said researcher Mirza Saquib Sarwar, a Ph.D. student in electrical and computer engineering at UBC. “Our contribution is a device that combines all those functions in one compact package."

The prototype measures 5 cm × 5 cm and uses inexpensive, widely available materials, including the gel and silicone.

John Madden (left) and Mirza Saquib Sarwar have developed a stretchable touch sensor that could pave the way for foldable devices of the future. Courtesy of the University of British Columbia.

"It's entirely possible to make a room-sized version of this sensor for just dollars per square meter, and then put sensors on the wall, on the floor or over the surface of the body — almost anything that requires a transparent, stretchable touchscreen," said Sarwar. "And because it's cheap to manufacture, it could be embedded cost-effectively in disposable wearables like health monitors."

The sensor could also be integrated in robotic "skins" to make human-robot interactions safer.

"Currently, machines are kept separate from humans in the workplace because of the possibility that they could injure humans. If a robot could detect our presence and be 'soft' enough that they don't damage us during an interaction, we can safely exchange tools with them,” said John Madden, professor in UBC’s faculty of applied science. “They can pick up objects without damaging them, and they can safely probe their environment.”

The UBC research was funded by the Natural Sciences and Engineering Research Council of Canada, and has been published in the journal Science Advances (doi: 10.1126/sciadv.1602200).