Self-healing materials: What can nature teach us?

Abstract

Natural materials such as bone and insect cuticle are capable of self-repair, a facility that greatly increases their durability and safe working stress. Some engineering materials have also been designed to be self-healing, although currently they cannot match the performance of natural materials as regards the efficiency and longevity of the healing process. In this paper, we review the state of the art regarding these two types of materials. We discuss the role of fracture mechanics in the development of theoretical models of self-healing; we identify certain crucial parameters that make natural materials successful and discuss how these lessons can be applied to improve the performance of self-healing materials for engineering applications.