Stretchable, flexible, and breathable MXene/dopamine/thermoplastic polyurethane nanofiber membrane with outstanding strain sensing and electromagnetic interference shielding performances

Outstanding strain sensing and electromagnetic interference (EMI) shielding performances are two important indicators for high-performance nanofiber membrane in flexible wearable electronic device. Here, simple electrospinning was employed to prepare the nanofiber membrane of thermoplastic polyurethane (TPU) as substrate. Then high-performance nanofiber membrane was developed by synthesizing dopamine on TPU nanofibers to form poly-dopamine (PDA) coatings (named PT) and ultrasonically loading MXene on PT (labeled MPT). Specifically, TPU substrate provides flexibility and breathability, PDA coating improves the adhesion between MXene and TPU, and MXene contributes to strain sensing and EMI shielding performances. Owing to the PDA coatings, MPT nanofiber membrane has outstanding EMI shielding efficiency (EMI SE) of 69.86 dB at 150 μm thickness and an absolute effective shielding value of 8383.33 dBcm2g−1. The combination of PDA with MXene improves the EMI SE of the MPT membrane by ∼ 1.6 times compared to other TPU-based membrane. MPT strain sensor exhibits great sensing performance with a remarkable detection threshold of 0.1%, strain coefficient of up to 2600, broad working range of 200%, and rapid response/recovery time (77/186 ms). Meanwhile, MPT strain sensor also shows remarkable ability to real-time monitor human health/motion, such as joint bending, breathing, speaking and heart rate, which makes significant contributions in the field of smart medicine. This nanofiber membrane can provide a universal strategy for the development of intelligent wearable medical devices.