Research Progress of Ultrathin Flexible Wearable Pressure Sensors

Abstract

Wearable electronics are evolving from simple motion-recording devices toward skin-conformal, textile-integrated, and continuously operating sensing systems. Pressure is a fundamental mechanical signal for pulse and respiration monitoring, plantar-force analysis, motion assessment, human-machine interaction, and electronic skin. Ultrathin flexible pressure sensors combine compliant substrates, micro/nanostructured sensing layers, and lightweight electrodes to maintain mechanical conformity while providing useful pressure responses. This review summarizes four major sensing mechanisms - piezoresistive, capacitive, piezoelectric, and triboelectric sensing - and integrates their material and structural design strategies into a unified comparison. Conductive composite networks, porous aerogels, bioinspired microstructures, nanofibrous films, PVDF-based piezoelectric materials, and self-powered triboelectric structures are highlighted as representative routes for improving electromechanical conversion. Typical wearable applications in physiological monitoring, gait and motion analysis, human-machine interfaces, and electronic skin are then discussed. Finally, the review summarizes remaining limitations in sensitivity-range trade-offs, long-term stability, multimodal signal decoupling, scalable manufacturing, and system integration, and outlines directions toward reliable and practical wearable sensing systems.