Smart Concrete can Compress and Generate Energy

A team of researchers at the University of Pittsburgh has developed metamaterial concrete for smart civil infrastructure systems. In particular, it can compress up to 15% under pressure while maintaining its structural integrity, as well as produce up to 330 microwatts of energy.

The material is made of reinforced auxetic polymer grids embedded in a conductive cement matrix. According to the team, this design causes contact electrification between the layers under mechanical action, which is further enhanced by the graphite powder that serves as an electrode in the system. It cannot produce enough power to be transmitted to the grid, but it could potentially be used to monitor damage inside concrete structures, such as in the event of an earthquake. Physically, the metamaterial itself can be fine-tuned to suit the needs of the assembly, changing its flexibility, shape, and brittleness.

“This project represents the first metamaterial composite concrete with supercompressibility and energy storage capacity. These lightweight and mechanically adjustable concrete systems could open the door for concrete to be used in a variety of scenarios, such as shock-absorbing engineering materials at airports to help slow planes down,” said Amir Alavi, assistant professor of civil and environmental engineering at Pitt.

In the future, this technology could power chips built into highways to help self-driving cars. But first, we need to decide how to insulate the energy-harvesting material integrated into the nanogenerator from environmental stressors such as humidity, wet weather, and temperature fluctuations.