23: Review on Self-healing Materials

Chapter 23 reviews self-healing materials. Briefly introduced and discussed in this chapter is a family of self-healing materials. The self-healing characteristics of these materials, and in particular, biomaterials, and the concepts of the self-healing processes in nature and biology, are already well known by scientific communities. One can start by describing their impact and occurrence in nature, in plants, in animals and human beings. These understandings of self-healing processes in biology and nature are particularly more advanced in terms of dermatology and skin repair by scar tissues, and they have further led to the most recent industrial applications and scientific discoveries. This chapter will introduce, describe briefly, and explain a wide range of self-healing smart materials. These materials will have internal structural abilities and characteristics that enable them to automatically repair damage to themselves with almost no external intervention or diagnosis. It is well recognized that using various materials over time will degrade them due to several phenomena such as fatigue failure, environmental degradation, or damage such as cracks, fracture, and creep that is incurred during operation. In general, internal cracks are difficult to detect, and manual intervention may be necessary. The advantage of self-healing materials is that they can treat material degradation by initiating a repair mechanism that responds to the incurred damage or degradation. Smart materials and structures also play important roles in self-healing materials because they are multi-functional and are capable of handling various environmental conditions.