The composite matrix is seeded with two dispersed phases: microcapsules holding a liquid monomer healing agent, and a separate catalyst phase suspended in the resin. A propagating crack physically ruptures any microcapsule it crosses, releasing the monomer into the crack plane by capillary action. Where that monomer contacts the catalyst, it polymerises in place and re-bonds the crack faces.
- Click the material to strike it — a jagged crack propagates edge-to-edge through the impact point and ruptures every capsule it passes near.
- Healing speed controls how fast the released agent cures once it starts flowing.
- Because only capsules along the crack path can release agent, and cured polymer never fully matches the original matrix, healed strength recovers most — not all — of what was lost, which matches real microcapsule composites (Nature 2001, White et al.).