Wall++: Turning walls into enormous touchpads

Walls generally don’t do much but stand, keeping your roof up and separating rooms. But since everything is becoming smart, why not your walls as well? Researchers from Carnegie Mellon University and Disney Research found that they could turn dull walls into smart walls using water-based nickel paint.

The smart wall could enable users to place or move light switches anywhere on the wall, or to control video games by using gestures. By monitoring the activity in the room, the system could, for instance, adjust light levels when the TV is turned on, or alert a user in another location when the laundry machine turns off.

Using simple painter’s tape, the researchers made a grid of diamonds, which tests showed is the most effective electrode pattern. They then applied two layers of conductive paint to the wall, removed the tape and applied the electrodes. They then finished the wall wit a topcoat for standard latex paint to improve durability and hide the electrodes.

To keep the costs low, the researchers used normal paint rollers and paint tape, and chose water-based nickel paint rather than more expensive conductive paints with silver.

The electrode wall can operate in two modes: capacitive sensing and electromagnetic sensing. In capacitive sensing, the wall functions like other touchpads – when a person touches the surface, the touch distorts the walls electrostatic field at that point. In the electromagnetic sensing mode, the electrode can detect the distinctive electromagnetic signatures of electric or electronic devices. This enables the system to identify the devices and their locations. This also goes for a person wearing a device that emits an electromagnetic signature; the system can track them.

The wall system hasn’t been optimised for energy consumption, but the wall-sizes electrodes consume about as much power as a standard touch screen.

For more touchpad made from household objects, click here.

Photos: Carnegie Mellon University / Disney Research