Self-healing flexible laminates for resealing of puncture damage

A flexible self-healing system capable of healing puncture damage has been manufactured. Our material consists of three layers: a poly(dimethyl siloxane) (PDMS) composite, embedded with a self-healing microcapsule system, sandwiched between two layers of poly(urethane) coated nylon. The total structure thickness ranges between 0.84 and 1.5 mm. A protocol is established in which samples are damaged using a hypodermic needle or a razor blade, and a successful heal is defined as the ability to reseal the damage to withstand a pressure differential across the laminate of 103 kPa (∼1 atm). Trends in healing success are analyzed as a function of microcapsule size, self-healing layer thickness, and puncture diameter. Healing varied significantly with microcapsule size, with the maximum healing success rate (100% successfully healed) occurring in samples with 220 µm microcapsules and a puncture diameter of 0.49 mm. For this puncture size, an increase in microcapsule diameter corresponds to a decrease in healing efficiency. However, samples with larger microcapsules (up to 500 µm avg.) demonstrate more effective healing for larger puncture diameters, up to 1.61 mm. Additionally, healing increased with composite layer thickness, and decreased with increasing puncture hole size.