Stretchable touch sensor opens way to future foldable devices
UBC-developed sensor uses highly conductive gel between layers of silicone that detects different types of touch even when it is stretched, folded or bent.
There is nothing worse than dropping your phone on the ground and picking it up only to find out that the screen is cracked, making it hard for sensors to pick up your finger’s touch. Smartphone manufacturers are looking for new was to ensure their phones are sturdy enough to stand up to everyday life.
Canadian researchers at the University of British Columbia (UBC) have developed an inexpensive sensor that could help make hyper-flexible touch screens a reality. The applications for this new development are endless, and researchers are already suggesting that these sensors could be used to make a foldable tablet or possibly an artificial skin that senses body movement and tracks vital signs.
The sensor uses a highly conductive gel sandwiched between layers of silicone that can detect different types of touch, including swiping and tapping, even when it is stretched, folded or bent. The current prototype measures only 5x5cm; however, researchers suggest that the sensors can scaled up, as they are working with materials that are both inexpensive and widely available.
“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,” said researcher Mirza Saquib Sarwar, a PhD student in electrical and computer engineering at UBC. “There are also sensors that are foldable, transparent and stretchable. Our contribution is a device that combines all those functions in one compact package.”
The development of malleable displays have been a focus of intense research interest over the last couple of years. Canadian researchers have pushed the technology to include smartphones that can bend and touchscreens that can flex. However, these new sensors may have applications that may make the technology even more accessible.
“It’s entirely possible to make a room-sized version of this sensor for just dollars per square metre, and then put sensors on the wall, on the floor, or over the surface of the body—almost anything that requires a transparent, stretchable touch screen,” said Sarwar. “And because it’s cheap to manufacture, it could be embedded cost-effectively in disposable wearables like health monitors.”
John Madden, Sarwar’s supervisor and a professor in UBC’s Faculty of Applied Science, suggests that the applications for these sensors goes well beyond smartphones and could 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,” Madden explains. “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, they can pick up objects without damaging them, and they can safely probe their environment.”
The research has been reported in Science Advances.