Bio-inspiration from naturally healing tissues

In the course of evolution, load-bearing biological materials have generally not evolved towards perfection and maximum strength, but instead developed high defect tolerance and adaptability [1]. Adaption occurs at various levels, see figure 1. While evolution leads to adaptation of entire species, each individual has mechanisms which confer some self-repair properties even at smaller scales to cope with a variety of environmental challenges. Healing and regeneration occur at the level of organs, but many biological materials are damage-tolerant at the supramolecular level or have (passive) self-repair properties