Department of Bioengineering, University of California, Riverside, Riverside, CA 92521, USA.
Nanoscale. 2018 Feb 8;10(6):2894-2901. doi: 10.1039/c7nr08296g.
Despite the significant potential of organic piezoelectric materials in the electro-mechanical or mechano-electrical applications that require light and flexible material properties, the intrinsically low piezoelectric performance as compared to traditional inorganic materials has limited their full utilization. In this study, we demonstrate that dimensional reduction of poly(vinylidene fluoride trifluoroethylene) (P(VDF-TrFE)) at the nanoscale by electrospinning, combined with an appropriate thermal treatment, induces a transformative enhancement in piezoelectric performance. Specifically, the piezoelectric coefficient (d) reached up to -108 pm V, approaching that of inorganic counterparts. Electrospun mats composed of thermo-treated 30 nm nanofibers with a thickness of 15 μm produced a consistent peak-to-peak voltage of 38.5 V and a power output of 74.1 μW at a strain of 0.26% while sustaining energy production over 10k repeated actuations. The exceptional piezoelectric performance was realized by the enhancement of piezoelectric dipole alignment and the materialization of flexoelectricity, both from the synergistic effects of dimensional reduction and thermal treatment. Our findings suggest that dimensionally controlled and thermally treated electrospun P(VDF-TrFE) nanofibers provide an opportunity to exploit their flexibility and durability for mechanically challenging applications while matching the piezoelectric performance of brittle, inorganic piezoelectric materials.
尽管有机压电材料在需要轻量和灵活材料特性的机电或机电器件应用中具有重要的潜力，但与传统无机材料相比，其固有压电性能较低，限制了其充分利用。在这项研究中，我们证明了通过静电纺丝将聚偏二氟乙烯三氟乙烯（P（VDF-TrFE））在纳米尺度上进行尺寸缩减，并结合适当的热处理，可显著提高其压电性能。具体而言，压电系数（d）高达-108 pm V，接近无机对应物的水平。由热处理的 30nm 纳米纤维组成的静电纺丝毡，厚度为 15μm，在应变 0.26%时可产生一致的峰峰值电压为 38.5V 和功率输出为 74.1μW，同时在超过 10k 次重复动作下保持能量产生。这种优异的压电性能是通过增强压电偶极子的排列和实现挠曲电的协同作用实现的，这两者都来自尺寸缩减和热处理的协同作用。我们的研究结果表明，尺寸可控和热处理的静电纺丝 P（VDF-TrFE）纳米纤维为利用其灵活性和耐用性来应对机械挑战应用提供了机会，同时可匹配脆性无机压电材料的压电性能。
