Category: Touch Insights
November 24, 2015

Touch screens are versatile and easy to use, but the slick surface is not great for some tasks - typing more than a quick e-mail, for instance - and becomes useless when your eyes are occupied with other tasks.

With all this in mind, researchers hailing mainly from the Technische Universität Berlin in Germany built a prototype of a touch screen with a layer of gel atop it that can change from soft to stiff when heat is applied - making it possible to create temporary buttons in all kinds of shapes that needn’t be defined in advance, which users can feel and use to interact with the display.

Such technology could make it easier to use a range of electronics, from in-car displays to smartphones and wearable gadgets, to do things like receive alerts or input information without needing to glance at the devices themselves. With the prototype, a seven-inch touch screen called GelTouch, researchers stiffened the gel into three basic shapes to form a grid of buttons, a slider, and a one-finger joystick button. 

To make GelTouch work, researchers used a heat-responsive hydrogel atop the display that is transparent and jelly-like until it’s heated above 32° C. Adding heat causes water to evaporate from the gel, collapsing and making it up to 25 times stiffer (while also turning it white). Researchers placed a layer of indium tin oxide (ITO), a transparent conductive film often used in displays, below the gel coating and connected electrodes to it. Then they used a few different methods to heat up the gel, including passing a current from one electrode to the next in order to harden the gel lying between them.

Read all about this technology in the published scientific paper.

News via MIT Technology Review