Turn Any Surface Into a Touchpad With a Coat of Paint

If you can paint it, you can turn it into a touchpad. Researchers from Carnegie Mellon have developed a system, dubbed Electrick, that can make just about any surface touch-sensitive. As TechCrunch reports, Electrick uses conductive paint and electrodes sensitive enough to detect the slight changes in electrical flow caused by a person’s finger.

To make the technology work, the researchers employed a technique called “electric field tomography.” When your finger presses against a touch-sensitive surface, like the screen of a smartphone, it absorbs a small amount of charge from that device. Your phone uses electrodes to sense disturbances in its electric field, and Electrick does something similar. Electrodes set up around a surface coated with conductive paint are able to measure the voltage differences caused when someone’s finger comes in contact with it.

Electrick works on most surfaces: Plastic, wood, drywall, Play-Doh, and Jell-O are all compatible with it. The system can be used to replace volume controls on steering wheels, pedals on guitars, and light switches on walls.

One area where the technology falls behind is accuracy. Electrick isn’t as well-suited for writing or sketching as other touchpads, but with a margin of error of one centimeter it’s a fine alternative for simple buttons and sliders. The researchers hope the system’s relatively low cost will make it available to a wide audience. “Our technique is readily accessible to hobbyists, requiring no special chemicals, equipment or facilities,” the authors write in their report . “Everything required can be readily purchased online."