A New Type of Smart Paint Could Help Engineers Monitor Structural Integrity

Dr. Mohamed Saafi of the University of Strathclyde in Glasgow, Scotland leads a team that has reportedly created a spray paint capable of detecting faults in large-scale structures such as bridges and mines. The paint, which is environmentally-friendly and made from fly ash and carbon nanotubes, is seen as a financial alternative to the instruments used now to detect small cracks in these structures. 

According to the report, the current instruments are very expensive and are limited to only looking at specific areas of the structure at different times. Whereas, this paint combined with an inexpensive electrode system will be able to monitor and detect faults across the structure in a whole scale manner. Also, when mixed, the paint has a cement-like property that will make it especially useful in harsh environments.

With this new technology, electrodes incorporated within the structure detect the bending or cracking and any significant change to the flow of electrical current within the bridge can be interpreted as a structural defect. Although the wireless communication nodes will run partially on battery, David McGahon, a researcher on the project, explained how the electrodes would stay cost efficiently powered by relying on energy-harvesting methods:

‘‘If you’re in a tunnel, you can use the vibrations of cars or trains going past to harvest power. If you’re on a bridge, you could maybe use a solar panel. The idea is to make it more sustainable so you’re not running out to your bridge or structure to change the battery all the time.’’

The team is also reportedly considering incorporating electrical impedance tomography (EIT) that will create a conductivity map, making it easier to monitor the entire structure and pinpoint exactly where on the structure a crack will appear. The first tests on structures for this “smart paint” will begin in the next two months.