The concrete that will change construction: it generates electricity and analyses homes.


Concrete is the material most commonly used in the construction industry in Spain. It is usually made from cement, sand and gravel or stone, but advances in technology have made it possible to use other elements to make it, such as eggshells or used tyres. Now, engineers are reinventing their design by using a multifunctional, lightweight metamaterial that can generate electricity on its own.

Scientists at the University of Pittsburgh (Pitt) in Pennsylvania, USA, aim to take concrete to a new level with a metamaterial – a heterogeneous collection of artificial materials that possess special electromagnetic characteristics – for the development of smart infrastructure. In their research, they present a new concept for lightweight, mechanically adjustable concrete systems that have the internal functionality of being able to sense, generate and harvest energy.

“The massive use of concrete in our infrastructure projects implies the need to develop a new generation of concrete materials that are more economical and environmentally sustainable, but offer advanced functionalities. We can achieve all these goals by introducing a metamaterial paradigm in the development of building materials,” says Amir Alavi, assistant professor of civil and environmental engineering at Pitt, in an official statement.

How it produces electricity
This is not the first time this group of researchers has worked with metamaterials, as in a previous project they used them in dental implants. This time, however, they have used this element to create a highly adaptable concrete, as attributes such as brittleness, flexibility and shape can be adjusted, allowing builders to use less material without sacrificing strength or longevity.

The metamaterial consists of networks of auxetic polymers reinforced within a matrix of conductive cement, which the researchers have enhanced with graphite powder to form the electrode, while a mechanical trigger or nano-generator can generate electrification by contact between the layers. That is, it can generate its own electrical charge.

It cannot yet produce enough electricity to send power to the grid, but the scientists do generate power that would allow it to power sensors embedded in roads, including future ones intended to help autonomous vehicles drive when GPS signals are too weak or when LIDAR technology is not working.

In addition to electrical output, it has the potential to be used to monitor damage within the structure of whatever is being built or to see the impact of phenomena such as earthquakes on buildings. Furthermore, physically the metamaterial itself can be adjusted to fit any construction, changing its flexibility, shape and fragility. According to tests carried out by the researchers, it could be compressed by up to 15 per cent while maintaining its structural integrity and produce 330 μW of power.

By El Español Diario.