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Video: Stretchy touchpad allows you to play piano on your arm

Even in these divisive times, there seem to be a few things we can all agree on: Babies are cute, stepping on a Lego is the worst, and we need new ways to play the latest video game on our gadgets. Although that third one may be a bit less universal, having electronics that can be used in and on our bodies could be useful for the medical industry and private consumers alike. To this end, researchers have created a new kind of touch panel that is both insanely flexible as well as biocompatible. The new technology is more electronically stable than current alternatives when stretched, and the materials don’t fatigue over time. The principle component of the new panel, hydrogel—a polymer network filled with water—is safe to use in and on the human body, having already found use in applications ranging from drug delivery to creating scaffolds for tissue engineering and wound healing. Because hydrogels are mostly water, the researchers were able to dissolve ions into the panel, permitting electricity to flow freely across it. When a finger makes contact with the surface, it grounds the circuit and sensors in each corner of the panel record the changes in current, which can then be used to calculate the location of the finger on the surface. As the researchers report online today in Sciencethe panel keeps working even when stretched 10 times its original area, and, as the video above shows, it can be used to play a virtual piano while molded around a human arm. The technology is far from perfected—it’s currently somewhat imprecise and there are questions about the material's durability over time—so you probably won’t become the next Chopin learning “Twinkle Twinkle Little Star” on the hydrogel keyboard, but the idea of one day having a flexible trackpad attached to our bodies might not be such a—wait for it—stretch.