Smart paper

University of Washington researchers developing a Smart paper that can sense the water leaks. The paper can use as a switch, which turns on or off an LED light or an alarm system that indicates the absence or presence of water.

“Water sensing is very challenging to do due to the polar nature of water, and what is used now is very expensive and not practical to implement,” said lead author Anthony Dichiara, a UW assistant professor.

Dichiara and his team implanted nanomaterials in paper for conducting electricity and sense the presence of water. For making smart paper, researchers manipulated the wood fibers and mixed in nanomaterials, but never used to make sensing papers.

Embedded nanomaterials in smart paper

However, the paper could detect the presence of water came by way of accidentally. Water droplets fell onto the conductive paper, causing the LED light indicating conductivity to turn off. At first, they thought they had ruined the paper, the researchers realized they had instead created a paper that was sensitive to water.

When water droplets touch the paper, its fibrous cells swell to up to three times their original size. That expansion displaces conductive nanomaterials inside the paper, which in turn disrupts the electrical connections and causes the LED indicator light to turn off. This process is fully unstable.

The researchers visualize an application in which a sheet of conductive paper with a battery could place around a pipe or under a complex network of intersecting pipes in a manufacturing plant.

If water leaks, the smart paper senses in the presence of water, then send a notice to a control center. So, user could quickly locate the leak.

Also, the paper is so sensitive. It can also detect large amounts of water in the composition of various liquids. This ability distinguishes water from other molecules particularly valuable for the petroleum and bio-fuel industries, where water is an impurity.

The smart paper is a hard and smooth in touch, and it looks rich black color because of the nanomaterials.

Source: [University of Washington]

Journal Source: [Journal of Materials Chemistry A]