Shao Zhuzhu, Zhang Xuan, Liu Jingfeng, Liu Xingang, Zhang Chuhong
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu, 610065, China.
Small Methods. 2023 Sep;7(9):e2300701. doi: 10.1002/smtd.202300701. Epub 2023 Jul 19.
Flexible piezoelectric energy harvesters (PEHs) have gained substantial attention owing to their wearability, breathability, and sustainable self-powered supply. However, existing film PEHs cannot identify forces in different bending directions, limiting their applications in wearable electronics and artificial intelligence. This study constructs a fabric PEH for the first time by introducing piezoelectric anisotropic BaTi O nanorods (BT2-nr) into piezoelectric polyvinylidene fluoride (PVDF) nanofibers with a bi-oriented architecture, in which BT2-nr uniformly aligns in the PVDF nanofiber during electrospinning. The dual-orientation feature endows the flexible PEH with anisotropy, which can sensitively identify the forces at different bending directions (e.g., bent vertically, parallelly, or twisted by 45° along the fiber orientations). Simultaneously, the composite PVDF/BT2 PEH containing 15 wt.% BT2-nr delivers an optimal piezoelectric output of 31.2 V with a high sensitivity of 5.22 V N . The developed anisotropic PEH can be used as a self-powered pressure sensor for multimodal intelligent biomonitoring of human movement. This study provides a feasible strategy for fabricating self-powered flexible PEHs with high electromechanical conversion efficiency and multifunctionality for wearable piezoelectric pressure sensors.
柔性压电能量采集器（PEHs）因其可穿戴性、透气性和可持续的自供电能力而备受关注。然而，现有的薄膜PEHs无法识别不同弯曲方向的力，限制了它们在可穿戴电子设备和人工智能中的应用。本研究首次通过将压电各向异性的钛酸钡纳米棒（BT2-nr）引入具有双取向结构的压电聚偏氟乙烯（PVDF）纳米纤维中来构建织物PEH，其中BT2-nr在静电纺丝过程中在PVDF纳米纤维中均匀排列。这种双取向特性赋予了柔性PEH各向异性，使其能够灵敏地识别不同弯曲方向（例如，垂直弯曲、平行弯曲或沿纤维方向扭转45°）的力。同时，含有15 wt.% BT2-nr的复合PVDF/BT2 PEH实现了31.2 V的最佳压电输出，灵敏度高达5.22 V/N。所开发的各向异性PEH可作为自供电压力传感器用于人体运动的多模态智能生物监测。本研究为制造具有高机电转换效率和多功能性的自供电柔性PEHs用于可穿戴压电压力传感器提供了一种可行的策略。
