Ultrahigh sensitive flexible sensor based on textured piezoelectric composites for preventing sports injuries

Textured piezoelectric composites (PCs) based on dielectrophoresis (DEP) reveal great merits in both improving sensitivity and maintaining flexibility, thus trending to be promising candidates for high sensitive flexible sensors. However, the DEP technique shows poor applicability in fabricating textured PCs with high filling content, which severely limits further improvement of piezoelectric performance. Herein, we propose a new strategy to enhance DEP force by decorating Cu nanoparticles on Ba 0.85 Ca 0.15 Ti 0.9 Zr 0.1 O 3 (BCZT) particles, thus textured BCZT@Cu/PDMS PCs with high filling content are obtained. The results proved that the enhanced DEP force is contributed by the excellent conductivity and capability of distorted electric fields of decorated Cu nanoparticles . Consequently, an ultrahigh piezoelectric voltage constant ( g 33 ) of 720 × 10 −3 Vm/N was achieved, which is much larger than that in other counterparts. Furthermore, the as-prepared piezoelectric sensor exhibits excellent sensitivity and flexibility, which can fit vulnerable joints like a band-aid seamlessly. On this basis, a flexible sport health monitoring system was developed, which shows great capabilities in real-time warn of the risky actions, rectification of wrong postures, and sports injury prevention.