Gradient Macro–Micro Structured PEDOT:PSS/Cotton Fiber Flexible Piezoresistive Sensor for Wide‐Range High‐Frequency Pressure Sensing

ABSTRACT As a pivotal component in wearable electronics, flexible piezoresistive sensors encounter performance optimization constraints stemming from creep effects in conventional materials and structural deformation heterogeneity. This study proposes a gradient structural design strategy for flexible piezoresistive sensors based on natural cotton fibers, establishing a macro–micro electromechanical coupling sensing mechanism through synergistic interaction between hierarchical microporous structures and macroscopic Z‐shaped multilayer folded configurations. By modifying cotton fibers with PEDOT:PSS (Poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate) conductive solution and employing physical imprinting and folding techniques, the fabricated sensor demonstrates exceptional performance metrics with high sensitivity of 0.704 kPa ⁻¹ , broad pressure detection range of 500 kPa, and superior linearity R ² of 0.99. SEM verifies uniform conductive particle distribution on fiber surfaces, effectively suppressing charge accumulation effects and ensuring continuous conductive network formation. Dynamic evaluations reveal outstanding frequency response characteristics within the 1800 Hz spectrum and remarkable stability under high‐frequency cyclic loading with merely a 3% variation coefficient. Practical validation through sign language recognition, finger flexion monitoring, and gait pattern discrimination confirms operational effectiveness in characteristic limb movement scenarios. Furthermore, comparative analysis demonstrates significant advantages over existing counterparts in static–dynamic performance and eco‐compatibility, presenting transformative solutions for medical diagnostics, human–machine interfaces, and intelligent wearable technologies.