Self-Healing Elastomers for Information Storage and UV-Sensing

Most electronic devices are composed of rigid and brittle components, which are typically not compliant and limit their applications. In contrast, flexible electronic devices are developed using compliant polymers to overcome the fracture problems of rigid devices, as well as to adapt to multiple conformations in a wide range of applications such as electronic skins, flexible displays, and tactile sensors. However, soft electronic polymer materials are typically vulnerable to mechanical damage caused by repeated use and accidental puncture with sharp objects, leading to functional failure. Therefore, self-healing materials provide an opportunity for repairing the damage and extending life-time. Herein, a self-healing polyurethane elastomer that is flexible, stretchable, and transparent was prepared. The self-healing elastomer relies on dynamic exchange reactions of disulfide bonds in its molecular structure upon activation with temperature. Inspired by the process of tattooing on human skin, a soft stretchable platform for reversible and irreversible information encryption was developed by microstructuring the polymer matrix with a functional dye solution. Upon the healing of the polymer, the dye was embedded in the polymer matrix, protected from abrasion and extraction with solvents. By storing a UV-sensing dye in the polymer matrix, we successfully produced a photochromic self-healing polymer elastomer, which exhibited a great potential for wearable technologies in harsh environments that require resiliency, protection, and in-situ repair.