3D‐Printed Flexible Piezoresistive Sensors for Stretching and Out‐of‐Plane Forces

Conductive polymer composites (CPCs) of carbon nanotubes (CNTs) and graphite nanosheet (GNP)-filled thermoplastic polyurethane (TPU) are 3D-printed into flexible piezoresistive sensors via fused filament fabrication. The sensor, with a customized lever-cross structure, allows detection stretching out-of-plane forces different magnitudes frequencies. force direction is obtained by combing the relative electrical resistance change in cross section sensor analysis. 75-CNT/25-GNP (CNT-to-GNP mass ratio 75%-to-25%) demonstrates excellent sensing performance at total nanoparticle loading 3 wt%. linearity 0.98, while those 100-CNT 50-CNT/50-GNP 0.93 0.86, respectively. gauge factor 52% higher than that its strain range 79% above sensor. Excellent stability demonstrated for after 1500 (out-of-plane force) cycles. synergistic effect CNTs GNPs on clearly shown this study.