These walls can talk – conductive paint makes surfaces smarter

Researchers have created low-cost smart walls that can detect gestures and track electrical appliances.

By using conductive paint, scientists at Carnegie Mellon University in Pennsylvania and Disney Research were able to transform normal surfaces for a cost of about $20 per square metre.

The wall can operate in two modes – capacitive sensing, like a touchscreen surface, or electromagnetic sensing, which allows it to identify electronic devices elsewhere in the area.

“Walls are usually the largest surface area in a room, yet we don't make much use of them other than to separate spaces, and perhaps hold up pictures and shelves,” said Chris Harrison, assistant professor in the Human-Computer Interaction Institute at Carnegie Mellon. “As the Internet of Things and ubiquitous computing become reality, it is tempting to think that walls can become active parts of our living and work environments.”

The technology, which researchers have dubbed Wall++, could be used to create light switches that can move around based on where’s most convenient, or automatically adjust light levels in a room when a TV is turned on. The walls could also track individuals wearing devices that emit electromagnetic signatures.

“Walls are large, so we knew that whatever technique we invented for smart walls would have to be low cost,” said Yang Zhang, a PhD student who will be presenting the research at the Conference on Human Factors in Computing Systems in Montreal this week.

The researchers used a low-cost water-based paint containing nickel, with masking tape to create a cross-hatched pattern on the wall, as tests showed this was the most effective pattern. After connecting the electrodes, they covered them with a layer of standard latex paint.