The field of wearables is rapidly expanding into just about every imaginable niche. You can already control your smartphone from your wrist using a smartwatch, and researchers are looking into turning your skin into a touchpad, so why not up the ante a bit and let users control any device they want from their forearm? The kind of device that would allow one to simply swipe on their skin would be somewhat cumbersome, as would any device with a self-contained touchpad. In light of those facts, scientists created a touchpad made of a special aerated gel that can be stretched up to ten times its surface area and into any shape, and still be used as a touchpad.
The gel touchpad comes courtesy of researchers at Korea's Seoul National University, and is made of polyacrylamide hydrogels; essentially, plastic-like polymers engorged with water. The touchpad can be stretched repeatedly and to a wide range of sizes and shapes, and can still retain conductivity. It works much like a traditional capacitive panel. Electricity flows at all times through the polymer, and the circuit is broken when a finger touches the panel. Other objects, like pencils, would not trigger a response from the panel. The magic happens thanks to lithium chloride salts trapped in the polymer, which help with conductivity.
After 100 cycles, the polymer begins to lose its touch sensitivity, but only to a very small degree. Scientists suspect this has something to do with water evaporating during use or over time, but thus far, testing on the matter has yet to prove anything. As a bonus, the panel can be used to display just about anything, since the aerogel used has a 98% transmittance rate for light. During testing, the panel was used with a piano app, a game, and as an input method for writing. Gestures like tapping, holding, dragging and swiping all worked fine on the aerogel. The current prototype lacks multi-touch capabilities, but according to team member Jeong-Yun Sun, the feature is planned for the next iteration, pending research into how to make it happen and make it feasible for use. The prototype touchpad is still in the earliest of stages, so consumers should not expect to see products based on it any time soon.