In addition to electricity production, it has the potential to be used to monitor damage within the structure of what is being built or to see the impact of phenomena such as earthquakes on buildings.
Scientists at the University of Pittsburgh (Pitt), in Pennsylvania (United States), intend to take concrete to a new level with a metamaterial —a heterogeneous set of artificial materials that possess special electromagnetic characteristics— for the development of smart infrastructures.
In their research, they present a new concept for lightweight and mechanically adjustable concrete systems that have the internal functionality to detect, generate, and collect energy.
“The massive use of concrete in our infrastructure projects necessitates the development of a new generation of concrete materials that are more economical and environmentally sustainable, yet offer advanced functionalities. We can achieve all of these goals by introducing a metamaterial paradigm into the development of construction materials,” said Amir Alavi, assistant professor of civil and environmental engineering at Pitt, in an official statement.
This is how it produces electricity
This isn't the first time this group of researchers has worked with metamaterials; they previously used them in dental implants. However, this time they've used this element to create a highly adaptable concrete, since attributes such as brittleness, flexibility, and shape can be adjusted, allowing builders to use less material without sacrificing strength or longevity.
This metamaterial consists of a network of reinforced auxetic polymers within a conductive cement matrix, which researchers have enhanced with graphite powder and which forms the electrode; meanwhile, a mechanical trigger or nanogenerator can generate electrification through contact between the layers. In other words, it can generate its own electrical charge.
It cannot yet produce enough electricity to send power to the electrical grid, but scientists do generate enough power to run sensors embedded in roads, including future ones designed to assist autonomous vehicles when GPS signals are too weak or when LIDAR technology is not working.
In addition to electricity generation, it has the potential to be used to monitor damage within the structure of what is being built or to observe the impact of phenomena such as earthquakes on buildings. Furthermore, the metamaterial itself can be physically adjusted to suit any construction, changing its flexibility, shape, and brittleness.
According to tests carried out by the researchers, it could be compressed up to 15% while maintaining its structural integrity and produce 330 μW of power.
“This project presents the first composite metamaterial concrete with supercompressibility and energy harvesting capabilities. These lightweight, mechanically adjustable concrete systems can open the door to using concrete in various applications, such as impact-absorbing engineering materials at airports to help slow out-of-control aircraft or seismic base isolation systems,” Alavi notes.
Scalable use
The project, which applies the material to various uses, involves scientists from Johns Hopkins University, New Mexico State University, the Georgia Institute of Technology, the Beijing Institute of Nanoenergy and Nanosystems (in China), and Pitt's Swanson School of Engineering, as well as working on achieving more properties and possibilities for the material.
They even point out that this multifunctional concrete they have created could become a widely used component in infrastructure, as it is "scalable, cost-effective, and can sustain its operations through green energy harvesting." At least that's what they state in their research, titled "Integrated Metamaterial Concrete Systems with Multifunctional Nanogenerators for Smart Civil Infrastructure," which has been published in the journal Advanced Materials.
Despite the potential of this concrete for creating smart, self-powered infrastructure, the researchers point out in their study the need for large-scale testing to improve the product. They also indicate that further research is needed on how to isolate the material integrated into the energy-harvesting nanogenerator from environmental stressors such as humidity, wet weather, and temperature fluctuations.
However, the research team has already partnered with the Pennsylvania Department of Transportation (PennDOT) to develop this concrete metamaterial with the goal of using it in Pennsylvania's roads in the future.
Source:https://www.elespanol.com/
