As powerful as touchscreen devices like smartphones and tablets have become, physical buttons and controls are often still a better way for users to interact with devices. (Think typing or playing action games.) So researchers at Texas A&M have come up with a novel way for touchscreens to feel more than just perfectly smooth by fooling a user’s sense of touch through temperature changes.
As folding screen devices become more reliable, more durable, and more commonplace amongst our mobile devices, there’s an assumption that one day laptops will become entirely touchscreen-driven, with virtual software keyboards replacing physical keys. It’s an idea that will potentially expand the usefulness of laptops (despite what Apple’s disappointing Touch Bar demonstrated). But being able to feel physical keys with our fingers is an important part of the muscle memory that allows many of us to type at impressive speeds without having to look down and hunt-and-peck on a keyboard.
There have been some interesting ideas proposed for making a touchscreen feel like the rows of physical buttons that make up a keyboard, including the use of microfluidic chambers that physically fill and inflate with oil to create 3D bumps on a screen that a user can feel as they type. Other approaches have leveraged ultrasonic vibrations to make touchscreens feel like they have a different texture, and even electroadhesion where the forces of static electricity can increase the amount of friction a fingertip feels as it slides across a screen. All of these solutions add quite a bit of complexity to a touchscreen, however, plus additional hardware costs, which manufacturers are always trying to minimize.
What researchers from the J. Mike Walker ‘66 Department of Mechanical Engineering at Texas A&M University are proposing will potentially be a lot easier to implement. In a recently published paper in the Science Robotics journal, they found that by regulating the temperature of the surface of a touchscreen, they can increase or decrease the amount of friction a finger feels like it’s experiencing. The sensation of friction can be increased by as much as 50% by increasing a touchscreen’s surface temperature from 23 degrees Celsius to 42 degrees Celsius, while the actual temperature changes are imperceptible to the user, assuming they’re sticking to taps or quick swipe gestures on the screen.
The current prototypes don’t facilitate temperature adjustments in fine detail, but the eventual goal is to be able to manipulate and quickly change the temperature on any region of a touchscreen so that as a finger is sliding across it the changes in friction that are felt fool the brain into thinking it’s feeling physical buttons like keyboards, playback controls, even joysticks and action buttons for gaming.
There’s a long way to go before this approach becomes a viable way to make virtual touchscreen keyboards easier to interact with. Being able to quickly heat and cool a specific region of a touchscreen almost instantaneously is, by itself, a monumental problem to solve, but given that folding screen devices are the latest trend that device makers are leaning on to sell premium hardware, there’s certainly the financial incentive to realize an approach like this.