Imagine a world where your walls can heal their own cracks. Not in some sci-fi future, but right now—in a lab in Montana—engineers are coaxing living systems to do just that. In a recent study published in Cell Reports Physical Science, researchers from Montana State University unveiled a new type of biomaterial composed of fungal mycelium and bacteria. It’s not just sustainable. It’s alive. And it may just point the way to a radical reinvention of how we think about materials, buildings, and even infrastructure.

The concept is as biologically elegant as it is industrially ambitious: Grow a scaffold using the root-like networks of Neurospora crassa, a fast-growing fungus, and then let bacteria move in to mineralize the structure—turning a once-soft form into something that starts to resemble bone. The result? A material that doesn’t just sit there, but lives for weeks. A material that could, in theory, maintain itself, patch its own fractures, or even help detoxify polluted environments.

“This is exciting,” says Chelsea Heveran, assistant professor and senior author of the study, “because we would like for the cells to be able to perform other functions.”

This is more than just a lab trick. Cement—the bedrock of modern civilization—is responsible for up to 8% of all CO₂ emissions from human activity. What Heveran and her team are chasing is a way to grow our buildings instead of baking them at thousands of degrees. The implications, if scaled, are enormous: a new kind of construction material that’s lightweight, low-energy, and capable of growing into complex forms.

Right now, the material holds up for about a month—an eternity in the world of living construction materials. Other bio-based materials tend to degrade in days or weeks. But longevity isn’t the only breakthrough here. “We created internal geometries that looked like cortical bone,” Heveran says. “Moving forward, we could potentially construct other geometries too.” That matters. Structure is everything in materials science. It’s what gives bone its combination of strength and flexibility. It’s what makes cement useful in bridges and skyscrapers. And it’s what synthetic biomaterials have typically lacked.

Enter Ethan Viles, the paper’s first author and a graduate researcher in Heveran’s lab. Inspired by mycelium’s earlier applications in packaging and insulation, Viles helped design materials with intricate internal architecture—a way of building living things that, in turn, can build other things. That recursive design philosophy could open the door to a class of materials that are not only resilient and environmentally friendly, but also programmable.

To be clear, this isn’t a plug-and-play concrete replacement—yet. As Heveran notes, “Biomineralized materials do not have high enough strength to replace concrete in all applications, but we and others are working to improve their properties.” The next step is extending the material’s lifespan even further and figuring out how to grow it at scale—possibly even on-site.

Still, this work marks a pivotal moment. It’s part of a broader shift toward what might be called bio-integrated architecture—design that doesn’t just take cues from nature, but invites nature in as a collaborator. Think of it as biomimicry, upgraded with a living engine.

In this case, the team isn’t just building materials. They’re cultivating possibilities. Possibilities that heal, that respond, that change with us. After centuries of treating our built world as inert and lifeless, maybe it’s time we invited a little biology back in.