Creating multifunctional concrete materials with advanced functionalities and mechanical tunability is a critical step toward reimagining traditional civil infrastructure systems.
Now, engineers from the University of Pittsburgh (Pitt) have introduced metamaterial concrete for the development of smart, civil infrastructure systems. In the new research, they presented a new concept for lightweight and mechanically tunable concrete systems that have integrated energy harvesting and sensing functionality.
“Modern society has been using concrete in construction for hundreds of years, following its original creation by the ancient Romans,” said Amir Alavi, assistant professor of civil and environmental engineering at Pitt, who is the corresponding author of the study. “Massive use of concrete in our infrastructure projects implies the need for developing a new generation of concrete materials that are more economical and environmentally sustainable yet offer advanced functionalities. We believe that we can achieve all these goals by introducing a metamaterial paradigm into the development of construction materials.”
The new metamaterial is made of reinforced auxetic polymer lattices embedded in a conductive cement matrix. The conductive cement, enhanced with graphite powder, serves as the electrode in the system, and a mechanical trigger can generate contact electrification between the layers.
The material cannot produce enough electricity to send power to the electrical grid, but the generated signal will be more than enough to power the roadside sensors. It can also be used to monitor damage inside the concrete structure or to monitor earthquakes while reducing their impact on buildings.
The research team conducted experimental studies to investigate the mechanical and electrical properties of the designed prototypes. The metamaterial concrete systems can compress up to 15% under cyclic loading and produce 330 μW of power.
Eventually, these smart structures may even power chips embedded inside roads to help self-driving cars navigate on highways when GPS signals are too weak or LiDAR is not working.
“This project presents the first composite metamaterial concrete with super compressibility and energy harvesting capability,” said Alavi. “Such lightweight and mechanically tunable concrete systems can open the door to the use of concrete in various applications such as shock absorbing engineered materials at airports to help slow runaway planes or seismic base isolation systems.”
The project team includes researchers from Johns Hopkins University, New Mexico State University, the Georgia Institute of Technology, the Beijing Institute of Nanoenergy and Nanosystems, and Pitt’s Swanson School of Engineering.
- Kaveh Barri, Qianyun Zhang, Jake Kline, Wenyun Lu, Jianzhe Luo, Zhe Sun, Brandon E. Taylor, Steven G. Sachs, Lev Khazanovich, Zhong Lin Wang, Amir H. Alavi. Multifunctional Nanogenerator-Integrated Metamaterial Concrete Systems for Smart Civil Infrastructure. Advanced Materials, 2023; DOI: 10.1002/adma.202211027