Background

In the 1990s, Dry (Citation1996), Dry and McMillan (Citation1996), Dry and Sottos (Citation1993) pioneered the development of hollow glass tubes as containers preloaded with an epoxy-based healing agent. In their research, when the hollow glass tubes cracked, the loaded healing agent filled the cracked surface and solidified. These hollow fibres can be regarded as one-dimensional (1D) vessels. Bleay, Loader, Hawyes, Humberstone, and Curtis (Citation2001) fixed hollow glass fibres with an external diameter of 15 μm and an internal diameter of 5 μm into a glass fibre-reinforced composite. It was found that negative effects on the mechanical properties of the host materials can be decreased (Trask, H. R. Williams, et al., Citation2007; Yuan, Citation2008) by reducing the size of the vessels. Vacuum-assisted capillary action filling was used to inject the healing agent into the small fibres (Yuan, Citation2008). Pang and Bond (Citation2005a, 2005b) filled 60-μm-diameter hollow glass fibres with a mixture of healing agents and UV fluorescent dye so that the "bleeding process" could be observed. These researchers constructed prototypes of 1D self-healing material structures based on hollow fibres, which are not only a healing agent container, but also a part of the reinforcing material.

• In 2007, three-dimensional (3D) vascular self-healing materials were developed by (Toohey, Sottos, Lewis, Moore, and White (Citation2007). The healing mechanism was ROMP reaction of DCPD enabled by Grubbs' catalyst and the healing efficiency varied from 30 to 70% in different healing cycles.
• Healing mechanisms for vascular self-healing composites are similar to those for capsule-based self-healing composites. For 1D vascular networks based on hollow fibres, the healing agent can be a one-part adhesive-like cyanoacrylate.
• The vascular structure has been applied in developing SHFRC. William et al. have focused on embedding hollow glass fibres and forming vasculatures inside fibre-reinforced composites, especially for sandwich structures.
• Cementitious materials with self-healing properties are another area where the vascular self-healing function is popular. Material designs have included a single vessel containing.

Understanding Self-repairing Textiles

The technology uses the plastic material polyurethane, which when applied in the liquid state to the surface of the textile that is underlying in the professional raincoat, eventually hardens. The coating is created by adding micro-capsules that are glue-like substances of the healing agent to liquid polyurethane, and on hardening creates a resilient bond with the textile. Hence when there is a tear in the coating, the capsules burst in the area that is damaged. The sealant when it comes in contact with the air and water hardens, and the coating seals itself. The experiments in the laboratory have produced positive results, but there are a few obstacles that need to be cleared before the product is commercially available. The fact that the textile material can heal tears more than a certain millimeter and how water-resistant are the micro-capsules in producing the glue-like effect need to be worked upon. Nonetheless, a novel technology like this has a lot of potential in the future of smart textiles.

Self-repairing textiles, utilizing technologies like nanotechnology and shape memory effects, are revolutionizing the industry by enhancing fabric durability and reducing waste. Innovations include self-healing coatings and rubber-like materials that mend tears with UV light or automatic processes, promising a more sustainable and long-lasting future.

The self-healing or the automatic repairing gave rise to the innovative idea of self-repairing textile materials. However, the concept of self-repairing has been common in the plastic, ceramic, and metal industries. Increasing the life of assets can be a huge cost-saving for consumers and will become a highly desirable product in any sector. There is a huge buzz around the business of self-repairing products. Around 200 papers have been published in the year 2011, generating curiosity everywhere. Re-healable polymers and composites are popular technologies being used to create self-repairing products in metals and ceramics.

Considered to be a concept that was pursued as science fiction by many in the textile industry is now a reality. An innovative layer of textile coating can now heal materials by sealing small holes and little tears in the surface layer. This technology has originally been made for waterproof workwear gear for professional fishermen. The teams of researchers and scientists from a Scandinavian country have developed this piece of intelligent raincoat.