Molecularly Engineered Self-Healing Polyimide with Dynamic Bond Exchange for Durable and Flexible Electronics

Abstract

Polyimide (PI) is a high-performance material with excellent thermal stability, mechanical strength, and chemical resistance, which makes it valuable for aerospace and electronics. However, prolonged cyclic mechanical stress can cause irreversible damage, reducing structural integrity and device lifespan. To overcome this challenge, an intrinsically self-healing PI is developed that enables rapid and efficient damage recovery for advanced electronics. By incorporating disulfide bonds and siloxane-containing aliphatic chains, we enhanced self-healing efficiency through dynamic exchange reactions and improved molecular mobility. The precise molecular design using two tailored diamines resulted in a glass transition temperature (T g) of 155 degrees C, tensile strength of 66.3 +/- 3.4 MPa, toughness of 4.4 +/- 1.4 MJ m-3, and 92% self-healing efficiency. This PI maintained mechanical integrity even after multiple healing cycles, ensuring long-term durability. With enhanced toughness and flexibility, this PI is a strong candidate for flexible electronics substrates. Additionally, Joule heating enables on-demand self-healing, providing a fast and energy-efficient repair strategy. This study highlights the superior self-healing, mechanical strength, and long-term durability of molecularly engineered PI, paving the way for next-generation flexible and wearable electronic materials.