How are biomimetic materials being used to create self-healing and resilient infrastructure?

Biomimetic materials take cues from how living things repair damage, manage moisture, or resist fractures. In infrastructure, the aim is not to make a bridge or road literally alive; it is to build repair mechanisms into the material so small damage is less likely to grow into an expensive failure.

Healing cracks in concrete and asphalt

In bacteria-based self-healing concrete, dormant bacterial spores and a food source are held in porous carriers or capsules within the concrete. When water enters a crack, the bacteria become active and help form calcium carbonate, which can fill or seal small cracks. This approach is being studied for structures where water ingress can lead to corrosion, including tunnels and bridges. Its performance depends on factors such as crack width, moisture, temperature, and how long the healing ingredients remain viable.

Other designs use capsules or vascular self-healing materials. A crack breaks a capsule or reaches a small internal channel, releasing a sealant or resin. A network of channels may be replenished and offer more than one repair cycle, although making such networks at scale without weakening the material remains challenging.

For roads, researchers have tested asphalt containing capsules of rejuvenating agents. When microcracks form, the released material can soften and restore some of the binder around them. Heat can also help asphalt close fine cracks. These methods may slow damage, but they do not replace resurfacing or repair of major structural defects.

Making structures tougher, not just repairable

Nature also inspires materials that resist crack growth in the first place. Nacre-inspired layered composites, for example, use alternating layers or interfaces that make a crack change direction and absorb more energy. Similar principles can improve the toughness of panels, protective layers, and components used in infrastructure. Water-repellent surface designs inspired by leaves can reduce wetting and help limit some forms of weathering, though they do not heal structural cracks.

For now, many of these approaches are still being evaluated in laboratory studies, pilot projects, or specialized products. Engineers need to confirm that a material heals reliably in real conditions, lasts through repeated weather and loading cycles, and meets safety and building standards. The most practical role for biomimetic materials is likely to be extending maintenance intervals and containing early damage—not eliminating inspection or repair.