Self-healing, photoluminescent elastomers for 3D printing fabrication of flexible sensors

Photoluminescent materials have garnered a lot of interest lately because of their many uses in chemical sensing, bio-detection, and optoelectronic devices. However, existing photoluminescent 3D printing materials exhibit deficiencies in mechanical properties, durability, and stability, hindering their adaptation to 3D printing of complex structures or stress-varying applications, while compromising the long-term stability of devices. To address these limitations, a photoluminescent self-healing elastomers containing dynamically hindered urea bonds were developed in this study, demonstrating excellent tensile properties (560 %), high strength (4.25 MPa), and good self-healing capabilities (95.45 % healing efficiency). The elastomer also exhibits unique photoluminescent characteristics, with luminous intensity varying under significant deformations. Photoluminescent characteristics are still present in 3D printed elastomers. Moreover, the elastomers can be utilized for 3D printing complex structures and customized sensors, with the printed sensors capable of achieving segmented responses. Resistive sensors prepared from this material exhibit high sensitivity and good cyclic stability, and they are capable of detecting various human motions while providing additional sensory information through changes in luminescent intensity. This study offers new insights into the development of photoluminescent self-healing materials for multifunctional applications, including smart wearable devices, dynamic displays, and optical sensors.