Tough, transparent, biocompatible and stretchable thermoplastic copolymer with high stability and processability for soft electronics

Materials with a variety of required properties, including stretchability, toughness, optical transparency, biocompatibility, processability, and recyclability are in great demand for soft electronics. Creation of such materials, however, has been hampered due to the challenges of balancing these properties. Herein, we report intrinsically stretchable thermoplastic copolymers with a random sequence of hard and soft domains in the polyimide backbone in which their superior traits are harnessed to enable the properties of the copolymer tunable and balanced. We obtained a tough and stretchable copolymer with high optical transparency, biocompatibility, thermal and chemical stability, and low water vapor transmission rate. In addition, the polymer is recyclable and shows excellent processability, allowing for the fabrication of fibers, thin films, and molded parts for soft electronics. Furthermore, the utility of the copolymer was successfully demonstrated for a wearable temperature sensor on the stretchable copolymer and a copolymer-based fully stretchable sweat collection patch, suggesting that they have great potential in soft electronics.