Bioinspired and Biomimetic Self-Healing of Advanced Composite Materials

INTRODUCTION Conceptual inspiration from nature is not new, and many engineering approaches can be considered to have been inspired by observing natural systems. The healing potential and repair strategies of living organisms is increasingly of interest to designers seeking lower mass structures with increased service life who wish to progress from a conventional damage tolerance philosophy. Naturally occurring ‘materials’ have evolved into highly sophisticated, integrated, hierarchical structures that commonly exhibit multifunctional behaviour [1]. Inspiration and mimicry of these microstructures and micromechanisms offers considerable potential in the design and improvement of material performance [2] but many of the biological processes involved are extremely complex. Bioinspired self-healing using hollow fibres embedded within a structure has been investigated at different length scales in several materials by various authors, e.g. bulk concrete [3-5] bulk polymers [2, 6], and polymer composites[7-10]. The latter has seen exciting developments in recent years, for example [1119], using the inspiration of biological self-healing applied with broadly traditional engineering approaches. Hollow glass fibres [20, 21] are used in preference to embedded microcapsules [22, 23] because they offer the advantage of being able to store functional agents for self-repair as well as integrating easily with and acting as reinforcement.