A new paint could detect stress in a structure (such as a wind turbine or bridge) and send wireless alerts to prompt a stitch in time.
Your wind turbine could soon be able to send you messages when it’s under stress. All you’d need to do is give it a spray-on coating of a new ‘smart paint’.
Researchers at Strathclyde University in Scotland believe this innovation could revolutionise the monitoring of structural safety. What’s more, their paint is made mainly from a cheap recyclate resource: the fly ash waste from power stations. It’s easy to apply and sets like cement, another advantage in the harsh environments where it’s likely to prove most useful.
Micro-cracks in a wind turbine’s concrete foundation, or points of stress on a bridge or down a mine, can herald huge problems down the line. But checking for tell-tale signs generally requires expensive instruments, involves lots of wasted time, and usually only examines particular parts of a structure. A smart paint job could get the whole thing covered in one go.
The clever part is the incorporation of highly aligned carbon nanotubes. With electrodes passing a current across the surface, these will show up any change in their alignment as a result of cracks, damage from pollutants or other sources of stress. As Dr Mohamed Saafi of the university’s civil engineering department explains: “The paint is interfaced with wireless communication nodes with power harvesting and warning capability, to remotely detect any unseen damage.” In other words, it’s a self-powered, Wifi-enabled solution.
The Strathclyde researchers have got as far as successful testing of a prototype. Software is being developed to draw a map of the electrical conductivity of the painted structure. It’s a novel application of electrical impedance tomography, a technique originally developed in medical scanning. “We are hoping that we can now demonstrate its effectiveness on a large structure”, Dr Saafi says. – Roger East
Photo: University of Strathclyde