Restorative powers

According to researchers at the University of Illinois, applying a food additive to damaged polymers can help restore them to full strength.

The repair process, in which solvent-filled microcapsules embedded in an epoxy matrix rupture when a crack forms, is a major improvement over an original self-healing process they had previously developed.

'While our previous solvent worked well for healing, it was also toxic,’ said Scott White, a professor of aerospace engineering and a researcher at the university’s Beckman Institute. ‘Our new solvent is both non-toxic and less expensive.'

During normal use, epoxy-based materials experience stresses that can cause cracking, which can lead to mechanical failure. Autonomic self-healing - a process in which the damage itself triggers the repair mechanism - can retain structural integrity and extend the lifetime of the material.

Designed to mimic the human body’s ability to repair wounds, self-healing materials release a healing agent into the crack plane when damaged, and through chemical and physical processes, restore the material’s initial fracture properties.