Smart paint could make bridges, mines safer

Scottish researchers are creating a low-cost smart paint that could detect microscopic faults in structures such as bridges, wind turbines, and mines.The paint, under development at the University of Strathclyde in Glasgow, is made of highly aligned carbon nanotubes, which can carry an electrical current, and a recycled waste product known as fly ash that's usually produced during coal combustion.

When mixed, the paint takes on a cement-like property that makes it hardy and particularly useful in areas where the weather can make regular safety monitoring difficult.

When the carbon nanotubes in the paint start to bend, their conductivity changes, indicating potential structural defects. The paint can be sprayed onto any surface, and wireless communication nodes attached to it allow it to remotely communicate unseen damage--micro-cracks in a wind turbine's concrete foundation, for example--hopefully before anyone gets hurt. The nodes will be partly powered by a battery, the Scottish scientists say, but could also rely on energy-harvesting methods such as solar panels or the vibration of trains passing through a tunnel.

"Current technology is restricted to looking at specific areas of a structure at any given time," Saafi said. "However, smart paint covers the whole structure, which is particularly useful to maximize the opportunity of preventing significant damage."David McGahon initiated the smart-paint project as part of his PhD project. The paint incorporates carbon nanotubes whose conductivity changes when bent.

Saafi and Ph.D. candidate David McGahon have developed a prototype of the paint and say tests have shown it to be "highly effective." They hope to conduct further tests in Glasgow in the next couple of months. "What we've done to date is to try to find the exact percentage of carbon nanotubes we need to make it cost effective," McGahon told U.K. publication The Engineer. "We've also done bending tests using strain sensors."

Source: news.cnet.comAdded: 31 January 2012