High-Performance Flexible Piezoresistive Sensors with Microhemisphere Electrodes and Electrospun Nanofibers

It remains a great challenge to achieve both high sensitivity and a broad linear sensing range simultaneously for practical application of flexible piezoresistive pressure sensors. Micro-nanostructures are highly effective in enhancing sensitivity, and yet they are inherently susceptible to deformation saturation under pressure due to size-dependent effects. In this paper, a high-performance flexible piezoresistive sensor is presented. This sensor incorporates flexible elastomer-based electrodes with hierarchical microhemisphere arrays and graphene nanoplatelets (GNPs) and a sensation unit consisting of a polyvinylidene fluoride (PVDF)/Ti3C2Tx MXene nanofiber membrane. Such design facilitates the sensitivity, mechanical robustness, and electrical stability. The resulting ESSIL/GNP−PVDF/MXene pressure sensor exhibits outstanding performance, including high sensitivity (1.442 kPa−1) over a wide detection range (0−0.25 kPa), fast response and recovery times (108 ms and 160 ms, respectively), and excellent dynamic stability over 1500 cycles. Notably, the combination of a wide linear range and high sensitivity marks a significant advancement. Additionally, the sensor ability to monitor complex human motionssuch as joint flexion, gait, and vocalizationdemonstrates its strong potential applications for health monitoring, wearable devices, and advanced human−machine interfaces.