"The process of monitoring involves, in effect, a wireless sensor network," Dr. Mohamed Saafi of the university's department of civil engineering said in a press release. "The paint is interfaced with wireless communication nodes with power harvesting and warning capability to remotely detect any unseen damage, such as micro-cracks in a wind turbine concrete foundation." The research team consists of Dr. Saafi and David McGahon, who initiated the work as part of his PhD project.
McGahon says energy harvesting methods might include using the vibrations of cars or trains going through a tunnel. "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 research team is also examining the possibility of incorporating electrical impedance tomography technology into a structure to help locate cracks. This technology creates a conductivity map. If a change in conductivity indicates a crack, a finite element model will show the exact location within the structure.
The team has developed a prototype, and the paint/electrode combination is undergoing testing. The researchers have been trying to discover the exact percentage of carbon nanotubes needed to make the product cost-effective. They have also conducted bending tests using strain sensors. Further tests will be carried out in the next couple of months.
gsmith, this paint was developed in the UK, not the US, and when I reported this it was in a prototype stage, so I doubt if it's being used here. However, some of the comments in the message board below list a few articles by Charles Murray on various US attempts at detecting faults in similar structures using wireless sensor networks.
Ann, do you know if this paint is currently being used on any bridges in the US? I can't remember the stats or which bridge, when the US last bridge collapsed a report indicated there were a lot of bridges that needed repair. This type of paint even if it is just in a testing phase would serve a good purpose. I would be most interested in the any report that would be created from data collected at the various test sites.
Chuck, thanks for the links and info on this form of energy harvesting. It's also interesting to hear that bridges are already being built with wireless sensor networks for detecting structural problems. This research was done in Scotland, though, and the study makes it sound like they don't have those installed there for remote fault detection.
Thanks for the links, Chuck. I see you were writing about this back in 2009. One interesting aspect is that some of this is made possible because of lower power needs from sensors and other devices. So the advances is not just greater ability to harvest energy, but also that not as much energy is required.
The fan is designed specifically for woodstoves. There are a few different brands, but they seem to be practically identical. They all come in two sizes and I have the "large" size. The fan is designed only to distribute the heat in one room; it's not powerful enough for more than that. Most heat sources aren't, except for whole-house forced air furnace systems. I've always thought those were unnecessarily and ridiculously complex and expensive.
The woodstove is our major source of heat. It's unhelpfully located at one end of the (smallish) house's long axis (and not relocatable without great hassle and expense), so two small ceiling fans distribute the heat farther. But the farthest rooms tend to get cold in winter. About half way from the stove is a forced air propane wall heater for backup, but I rarely use it except on winter mornings before the woodstove cranks up. I hear that Vermonters adhere to the same principal as Scots and Brits: "put on a sweater!" Sounds like us here at my house.
DIY candy, journeys to Mars, coding for road trips, and more. These STEM (science, technology, engineering, and math) activity options will keep kids engaged this summer, from 10-minute activities to more advanced undertakings.
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