Researchers at the University of Strathclyde in Glasgow have developed a low-cost paint that, when coupled with electrodes, can detect tiny faults in bridges, mines, wind turbines, and the like before a major structural failure can occur. David McGahon developed the project for his PhD, alongside Dr. Mohamed Saafi.
“Speaking to Wired.co.uk, Dr Saafi explains that when a wireless sensor network is connected up to the paint, the resultant system is able to detect microscopic faults. “The electrodes connected to the paint act almost like the nerves in the human body,” he says. They will pick up of any changes in the conductivity map — and these changes can be caused by cracks. The electrodes will also pick up on motion, which can indicate structural weakness as well as corrosion.”
The paint is made using fly ash and carbon nanotubes aligned in a precise manner which are capable of carrying an electrical current. When a structural deficiency occurs in the structure, the nanotubes will start to bend. This will cause a change in the conductivity of the current and engineers will be able to pinpoint the location of the structural deficiency. Due to the contents of the paint, this is also an environmentally friendly product.
Typically, the process of monitoring the structural integrity of these types of structures can be quite costly. It involves heavy equipment such as lifts and highly trained personnel. The inspections are also visual, so most cracks and faults are not detected until they can be seen with the naked eye. At this point, the structure will mostly likely need more money to fix, and the safety of the structure may already be in question. The new smart paint will help detect areas of concern possibly even before they become a threat to the structural integrity of the structure, and hopefully this will help prevent failures and costly repairs.
A prototype paint has been developed and the team hopes to test this paint on major structures in the coming year.