Spray Paint Turns ANYTHING Into a Touchpad

Researchers at Carnegie Mellon University say they can turn virtually anything into a computer touchpad by using a conductive spray paint.

The technology is simply a more ambitious implementation of how touchscreens already work. While older ‘resistive’ screens worked by the user physically pressing down a screen until it contacted a second layer beneath, modern capacitive screens involve the finger disrupting an electrostatic field on the surface of the screen.

The researchers had the idea that in theory this should work on any surface and the challenge was simply how to apply the electrostatic field. They developed Electrick, a spray paint modified to conduct electricity and paired it with a series of electrodes that attach to the edges of the sprayed surface. By applying a current to one electrode and measuring the voltage at each of the others, the system spots the variation in the individual voltage readings when the surface is touched and in turn deduces the location of the finger.

The big drawback of the system is that it can only detect the finger press to within one centimeter, so it’s more suited to use as a simulated slider or button than for precise inputs. Among the surfaces successfully tested with the spray paint were a sheet of plasterboard, a guitar, some Play-Doh (presumably not played with after spraying) and even a Jello mold of a human brain.

The research found the coating was resilient enough for the testing at least, not suffering any loss of performance after almost 900 touches. However, the accuracy was decreased when the testing took place near to fluorescent lighting.

It’s not entirely clear how easily the technology could be adapted to real world products, though some possibilities include making interactive toys or turning car dashboards into touch control panels. It might also make it easier or cheaper to build prototypes of touch-based devices.