Known for being smooth, glass panes are found in fronts of virtually every smartphone and tablet in the market today. However, that smoothness can also become its undoing especially for users trying to manipulate virtual buttons and knobs. According to IGI plotter experts, researchers from Northwestern University think they have found a way on how to offer tactile feedback on a sheet of glass so that the computer screen could not only show what something looks like but also offer a sense of tactile feeling.
About 10 years ago, researchers at Northwestern’s mechanical engineering department found a way to develop a device that can show virtual shapes and textures e.g. Buttons on a touchscreen. They named this device TPaD and it uses ultrasonic waves to a thin glass plate placed over the screen & decreased the friction between the fingertip and the plate. The result? it made the glass feel much more slippery.
Researchers needed to understand how the whole thing works so they can come up with practical applications. According to sculpted patterning experts, there are two competing hypothesis with the first one stating that the vibrating plate was the one that caused the thin film of air beneath the fingertip to compress and thus creating the pressure needed to levitate the skin of the finger off the screen. The second hypothesis calls for the use of ultrasonic vibrations as the cause to why the skin bounces off the surface of the glass.
Researchers from Northwestern built a prototype model or test device, which was essentially a fingerprint imager and connected it to the TPaD, the result showed that both theories were in part true. The result showed that the reduced friction or slipperiness of the glass was caused by the skin bouncing, not on the glass plate but on a layer of air that was trapped between the plate and the surface of the finger. To put it simply, the fingertip is actually bouncing on air.
Researchers now plan to develop new algorithms in order to discover more accurate textures that can lower the power consumption of new kinds of haptic devices. They also want to develop technology that will be used to align fingers of the visually impaired over a keyboard in order to give them more control of what they are typing on screen.