Self-healing material has role as defect-tolerant structural component

Dubbed SAC (self-adaptive composite), the material from Rice University is made by mixing two polymers and a solvent that evaporates when heated, which leaves a porous mass of sticky spheres. When cracked, the matrix repeatedly heals and returns to its original form after compression.

The labs of Rice materials scientists Pulickel Ajayan and Jun Lou led the study that appears in ACS Applied Materials and Interfaces. They suggested SAC might be a useful biocompatible material for tissue engineering or a lightweight, defect-tolerant structural component.

Other self-healing materials encapsulate liquid in solid shells that leak their contents when cracked.

“Those are very cool, but we wanted to introduce more flexibility,” said Pei Dong, a postdoctoral researcher who co-led the study with Rice graduate student Alin Cristian Chipara. “We wanted a biomimetic material that could change itself, or its inner structure, to adapt to external stimulation and thought introducing more liquid would be a way. But we wanted the liquid to be stable instead of flowing everywhere.”