Biomimetic planar and branched self-healing networks in composite laminates

The healing potential and repair strategies of living organisms is increasingly of interest to composite 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 (e.g. damage tolerance and self-healing). Inspiration and mimicry of these microstructures and micromechanisms offers considerable potential in the design and improvement of material performance. Most self-healing work to-date has been bioinspired and not biomimetic, although this is now changing. This paper will present the concept of biomimetic planar and branched self-healing networks formed in carbon fibre reinforced polymer composite laminates. The actual location and housing of the healing network is instrumental to the success of this approach. The paper will also discuss the role of damage compartmentalization with self-healing attributes, the most likely short-term approach for the introduction of a self-healing concept in the safety-critical aerospace composites industry.