Scientists at the University of Washington have designed smart paper capable of sensing water and conducting electricity. The paper could be used to detect water leaks in city pipes.
Even small leaks in a city’s maze of pipes can prove costly. Left alone, the problem can get worse. And finding the leak can prove timely. The American Water Works Association estimate leaks cause 250,000 water line breaks every year, costing public water utilities an annual sum of $2.8 billion.
Scientists hope their new smart paper can shrink those costs by making it easier to find and fix leaks. The paper can sense the presence of water and conduct an electric current to sound an alarm or trigger a light, alerting maintenance authorities to the presence of a leak.
The scientists used the standard papermaking process but mixed the wood fiber pulp with nanomaterials capable of detecting water and conducting current.
The technology originally came about by accident. Researchers were simply trying to make a paper capable of powering an LED light. When a few drops of water spilled onto their paper, the light was disrupted. The scientists thought they’d ruined their technology. In fact, they’d created water-sensitive paper.
The water swells the fibrous wood cells disrupting the current, but as the paper dries, the nanomaterials reform the conductive network.
The paper can also be designed to trigger a current when it detects water. Researchers believe the paper could be outfitted with a battery and wrapped around pipes or positioned between complex intersections of pipes. When the paper detects a water leak, a current will alert maintenance workers.