Reviewed by Lexie CornerMar 24 2025
Researchers at the University of Southern California (USC) have developed a method inspired by coral reefs to capture atmospheric carbon dioxide and convert it into durable, fire-resistant building materials. This approach, described in npj Advanced Manufacturing, presents a potential solution for carbon-negative construction.
The resulting mineral-polymer composites demonstrate high mechanical strength, fracture toughness, and fire resistance.
Image Credit: Darwish.Studio/Shutterstock.com
This is a pivotal step in the evolution of converting carbon dioxide. Unlike traditional carbon capture technologies that focus on storing carbon dioxide or converting it into liquid substances, we found this new electrochemical manufacturing process converts the chemical compound into calcium carbonate minerals in 3D-printed polymer scaffolds.
Qiming Wang, Associate Professor, Civil and Environmental Engineering, Viterbi School of Engineering, University of Southern California
Inspiration of Coral Reefs
Most current carbon capture methods focus on either storing carbon dioxide or converting it into liquids, which tend to be costly and inefficient. This new approach integrates carbon capture directly into construction materials, offering a more cost-effective alternative.
Wang attributed the “magic of ocean coral” as fundamental to the study’s breakthrough.
As an organism, coral can use photosynthesis to capture carbon dioxide from the atmosphere and convert it into a structure.
Qiming Wang, Associate Professor, Civil and Environmental Engineering, Viterbi School of Engineering, University of Southern California
The process was inspired by the way coral forms its aragonite skeletons or corallites. Coral naturally creates these structures through biomineralization, a process in which it absorbs carbon dioxide from the atmosphere via photosynthesis. The coral then combines this carbon dioxide with calcium ions from saltwater to precipitate calcium minerals around organic templates.
In the study, the team used 3D-printed polymer scaffolds designed to mimic the organic templates of coral. They applied a thin layer of conductive material to these scaffolds and submerged them in a calcium chloride solution. The structures were then connected to electrochemical circuits as cathodes.
When carbon dioxide was introduced into the solution, hydrolysis occurred, producing bicarbonate ions. These ions reacted with calcium in the solution, gradually filling the 3D-printed pores with calcium carbonate. This process resulted in a dense mineral-polymer composite as the final product.
Fire Resistance
The experimental composite material's response to fire was one of its most unexpected features. Despite the 3D-printed polymer scaffolds lacking intrinsic fire resistance, the mineralized composites performed well in the experimental flame tests conducted by the research team.
“The manufacturing method revealed a natural fire-suppression mechanism of 30 minutes of direct flame exposure. When exposed to high temperatures, the calcium carbonate minerals release small amounts of carbon dioxide that appear to have a fire-quenching effect. This built-in safety feature provides significant advantages for construction and engineering applications where fire resistance is critical,” said Wang.
Cracked structures made from this material can be repaired by connecting them to low-voltage electricity, which also enhances their fire resistance. Electrochemical processes can restore the mechanical strength of fractured interfaces.
Carbon-Negative Future
negative carbon footprint, meaning the carbon captured was greater than the carbon emissions from operations and production.
The researchers also demonstrated how the produced composites could be modularly assembled into larger structures, enabling the creation of large-scale load-bearing systems. These composite materials may be useful in construction and other fields where high mechanical resistance is required.
According to Wang, the researchers plan to focus on making the patented technology commercially available. The study's innovative manufacturing technique opens the possibility for creating carbon-negative structures, which is significant given that construction and building materials account for about 11 % of global carbon emissions.
Journal Reference:
Deng, H., et al. (2025) Towards negative carbon footprint: carbon sequestration enabled manufacturing of coral-inspired tough structural composites. npj Advanced Manufacturing. doi.org/10.1038/s44334-024-00012-x