The smart brick. Image: D'Arcy Laboratory, Department of Chemistry, Washington University in St. Louis
Bricks are about as basic as architectural materials can get, yet these simple building blocks have hidden powers that can be leveraged to provide electricity, according to a new study. Scientists modified a common red brick—the same kind you’ll find on sale for under a dollar at your local hardware store—so that it could power a green LED light. This proof-of-concept for a “smart brick” reveals that brick technology, which dates back thousands of years, can be tweaked to have futuristic applications, including electrical conductivity and sensing capabilities. The results were published on Tuesday in Nature Communications.
“We have created a new brick that can be incorporated into your house that has the functionality of storing electrical energy,” said study co-author Julio D'Arcy, assistant professor of chemistry at Washington University in St. Louis, in a call. “We are thinking that sensing applications is a low-hanging fruit for these bricks,” he added. For years, D’Arcy and his colleagues have experimented with rust, the ubiquitous reddish film that forms on any structure that contains iron. Rust is normally seen as a corrosive nuisance, but D’Arcy’s team has shown that rusty iron oxides have useful properties for material science.“We discovered that if you actually treat rust chemically, it actually becomes reactive,” D’Arcy explained. “So something that we typically think of as waste turns out to be a useful chemical for producing materials that can be used for storing energy.”The pigment in red bricks is partially derived from rust, which inspired the researchers to take a closer look at the structural properties of bricks to see if they could be converted to an energy-storing device called a supercapacitor.The intricate porous interiors of bricks turned out to be an ideal space to introduce sophisticated polymer coatings, which react with rust to increase the surface area and conductivity of bricks.
As a result of the modifications, the team was able to engineer a prototype smart brick that stored enough energy to power the green light. The team is currently building on its findings by manufacturing specialized bricks with various metal oxides and polymer coatings.
In addition to tinkering with conductivities and storage capacity, the researchers hope to demonstrate that air sensors or water purification systems could be integrated into the bricks.“When the water runs down your rooftop and it goes through the brick, what if the water gets purified when it comes down and you finally collect it?” D’Arcy speculated. “We always think about purifying water on a filter. But what if the house was a filter?”In the near-term, however, D’Arcy and his colleagues are focused on boosting the efficiency of these bricks so that they could be incorporated as a back-up power source in regular homes, such as an emergency lighting system.“If we can increase the amount of energy that can be stored in one brick,” D’Arcy said, “we can scale up and use even less bricks.”