Spray-On Touch Screens? How to Turn Any Flat Surface into a Touchpad

With just a can of spray paint, researchers can turn flat surfaces of any shape or size —

ranging from walls to furniture to even musical instruments — into touchpads, according to a new study. The technique, dubbed Electrick by its inventors from Carnegie Mellon University in Pittsburgh, relies on electrodes attached to an object made of or coated with any slightly conductive material. While not as precise as smartphone touch-screen technology, the resulting touchpads are still accurate enough to allow basic control functions, such as using a slider or pushing a button, the researchers said.Researchers turned the surface of this guitar into a touchpad. Credit: Carnegie Mellon University Smartphone touch screens are made of expensive materials and require costly and sophisticated techniques to build. As such, it can be complicated to create touch surfaces on objects that are large or irregular in shape, Zhang said. There are ways to enable touch control on larger objects, but these methods mostly rely on detection of motion by cameras. However, these techniques also have limitations, Zhang said. "If you use a camera, it won't work that well if the lighting condition changes," he said. "Users also could have privacy concerns to have cameras in their homes." Zhang added that the Electrick technique enables touch control in objects that have been created using a wide range of manufacturing methods, including 3D printing and injection molding. The only condition is for the material to be slightly conductive, he said. "It wouldn't work with normal plastic, which is totally nonconductive," Zhang said. "But we can use various carbon-loaded materials, materials that have carbon particles inside them, which make them slightly conductive." The slightly conductive layer can also be sprayed onto the surface of an otherwise-nonconductive object of any shape, Zhang said. This way, the engineers can enable touch control in existing pieces of furniture, make a touch-controlled steering wheel or phone case, or enable someone to turn on the lights in their apartment by simply tapping the wall. Zhang said the Electrick surfaces are durable and could get additional protection by adding an extra layer of coating on top. The researchers presented the technology earlier this month at the ACM Conference on Human Factors in Computing Systems in Denver. Original article on Live Science.       https://www.livescience.com/59278-turn-any-flat-surface-into-touchpad.html