1. Blood Clots and Vascular Networks: Self-Healing Materials

Perhaps one of the biggest differences between most living organisms and engineered materials is the ability to adapt and heal in response to damage and degradation (Nosonovsky, Self-repairing materials. In: Bhushan B (ed) Encyclopedia of nanotechnology. Springer, Netherlands, pp 2382–2385, 2012). Because engineered materials generally lack the inherent ability to fix themselves and deteriorate over time due to degradation, engineers are researching and developing self-healing materials—materials that can recover from damage without external intervention—in hopes that this will not be the case for certain applications in which self-repairing ability would be particularly advantageous (Ghosh, Self-healing materials: fundamentals, design strategies, and applications. In: Ghosh SK (ed) Self-healing materials: fundamentals, design strategies, and applications. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, pp 1–28, 2009). Though healing mechanisms of living organisms are extremely complex, making it difficult to mimic them, nature is a source of bio-inspiration for researchers who are seeking to create self-healing materials for the future of engineering. One such source of bio-inspiration includes blood clotting, which has taken the form of encapsulation (White et al., Nature 409:794–797, 2001) and hollow glass fibers in self-healing materials (Trask et al., Bioinspir Biomim 2(1):1–12, 2007). Vascular systems are another source of bio-inspiration and have led engineers to create circulatory concepts that also enable self-healing (Andersson et al., Self healing polymers and composites. In: van der Zwaag S (ed) Self healing materials. An alternative approach to 20 centuries of materials science. Springer, Netherlands, pp 19–44, 2008). This chapter shows how and why engineers used these natural mechanisms to develop self-healing materials and delves into the ways these self-healing materials can revolutionize the field of engineering and technology with a variety of applications ranging from self-repairing glass, corrosion protection, innovative aerospace composites, and more.