Monitoring micro fractures on airplane parts and checking the physical integrity of infrastructure has now become much easier and more accurate thanks to carbon black tech.
Cheaper to build, and lighter; dense sensor net using the new material offers a cost-effective solution…
Researchers from the Hong Kong Polytechnic University have developed a bold and innovative type of sensor based on nanocomposites. These can be used on flat or curved structural surfaces and networked to deliver data in real-time. It is a lightweight material with a low-cost fabrication and implementation method, allowing for large quantities to be used in a sensor network. The data gathered can be easily analyzed for structural flaws in trains, airplanes, ships, bridges and train tracks.
The material, discovered by Department of Mechanical Engineering, led by Professor Su Zhongqing and Professor Zhou Limi, makes use of a hybrid of conductive nanoparticles, polyvinylidene fluoride (PVDF), 2D graphene, and carbon black. The resulting nanocomposite sensor can be applied to different sizes of structures and engineering applications, even on a moving vehicle.
Alternatively, it can be applied from a moving vehicle onto a track or any large structure, like bridges for example. The sprayable nature of the material allows it to be spread over a large area for real-time monitoring of the stresses on various materials.
Carbon Black Tech
The sensing technology is composed of the nanocomposite sensor coupled with an ultrasound actuator. The actuator uses guided ultrasonic waves (GUWs) which are picked up by the sensors. The GUWs generated as they travel through the monitored material show discrepancies when they encounter a break (a microfracture or a fissure). This leads to a wave scattering of the GUWs. And that in turn provides readings from the sensors that enable engineers, researchers, or maintenance personnel to the discover the location of the break.
Conventional sensors using ultrasound cost more than $10 each and weigh a few grams. These are made of lead zirconate titanate (PZT) and are limited in use by their cost and weight. These are usually stiff and cannot be used on curved structural surfaces. The host material is also penalized with the additional weight of numerous sensors required to do the job.
In comparison, the nanocomposite sensor is expected to cost less than $0.50 each and weigh 0.04 grams. These can also be manufactured in large volume to create a much denser sensor network than conventional ultrasound sensors. Cheaper to build, and a light sensor net using the new material offers a cost-effective solution where more data can be gathered over a wider range of structures.
The added bonus to using the nanocomposites is that the structure can be moving or in use while being monitored, eliminating downtime or the requirement to shut down operations just to do the check.