High-sensitivity and ultra-broad linear working region flexible piezoresistive pressure sensors based on PDMS/CNT/TPU

Designing and fabricating flexible piezoresistive pressure sensors (FPPS) with simultaneous high sensitivity and a broad linear working region remains a considerable challenge. In this work, thermoplastic polyurethane (TPU) fiber films were first prepared via electrospinning. Then, the CNTs were anchored onto the surface of a TPU fiber films via ultrasonication as the driving force. Finally, polydimethylsiloxane (PDMS) was used to modify the CNT/TPU and obtain the PDMS/CNT/TPU composite materials. The electrical and mechanical properties of CNT/TPU and PDMS/CNT/TPU were studied. The sensor performances of FPPS based on CNT/TPU and PDMS/CNT/TPU were analyzed and compared. These results prove that the sensitivity of FPPS is significantly improved after the PDMS modification. The optimized PDMS/CNT/TPU FPPS has a sensitivity of 1.43 kPa −1 in a ultra-broad linear working region of 0–2500 kPa and cycling stability over 6000 cycles. FPPS has been successfully used to monitor physiological signals and human movements, which indicates great potential for wearable electronics and human-machine interfaces.