Scientists Develop New ESM Recyclable Building Material: Absorbs CO2 During Production

The material is called "Enzymatic Structural Material" (ESM), which is produced through a low-energy, bio-inspired process that can cure and form within a few hours, and features adjustable strength and recyclability. The relevant results were published in "Matter" on December 3rd.

The research is led by Professor Nima Rahbar, head of the Department of Civil, Environmental, and Architectural Engineering at WPI. The team uses an enzyme that can convert carbon dioxide into solid mineral particles, and then these particles are bonded and solidified under mild conditions to form structural materials.

Compared to traditional concrete, ESM has a significantly faster curing speed and a substantial reduction in carbon emissions. The production of traditional concrete requires high-temperature roasting of clinker at over 1450°C and takes weeks to fully cure, with its manufacturing process accounting for nearly 8% of global CO₂ emissions.

Researchers indicate that producing 1 cubic meter of ESM can sequester over 6 kilograms of carbon, while the same volume of traditional concrete emits about 330 kilograms of CO₂. In addition to the difference in carbon emissions, ESM's rapid forming, adjustable strength, recyclability, and reparability give it application potential in areas such as wall panels, roofing structures, and modular building materials. Its reparability also helps to reduce long-term waste associated with maintenance.

In the context of seeking low-carbon materials in the global construction sector, research teams point out that the way humans rely on concrete urgently needs to change. Existing alternative strategies, such as the use of supplementary materials like fly ash and silica fume, low-carbon fuels, or carbon capture technologies, have limitations in terms of raw material supply, cost, and performance. Solutions like microbially induced calcite precipitation (MICP) are also constrained by environmental impacts and complexity. Although bamboo, fungi, and other biological materials have garnered attention, they have not yet met the engineering strength and durability requirements.

The ESM demonstrated in this study employs a novel process to construct a stable hydrophobic carbon skeleton microstructure by forming a capillary suspension and undergoing thermal curing. This allows the material to combine sand particles at optimal porosity and fix calcium carbonate generated by enzymes, thereby enhancing water resistance, compressive strength, and structural forming ability. These characteristics make ESM perform better than existing bio-based building materials and significantly reduce overall carbon emissions.

The research team believes that the lightweight, rapid-forming, and low-energy consumption characteristics of ESM can be applied in scenarios such as disaster relief, affordable housing, and climate-resilient infrastructure in the future, aligning with circular manufacturing and global carbon reduction goals. Although further testing and large-scale validation are still needed, this technology has taken an important step toward "carbon-negative buildings," which not only reduces emissions but also actively absorbs carbon dioxide from the environment during the production phase.