Electrospun piezoelectric polymer fibers, which offer mechanical flexibility, light weight, and relatively low temperature processing, have emerged as a strong solution to shape-adaptive energy harvesting and sensing applications for smart electronics at multi-scales. In this work, we aim to enhance the electrospun fiber-based piezoelectric energy harvesting performance by elucidating the role of the solvent in crystallization kinetics and fiber formation during electrospinning as well as its influence on harvesting performance. Two key solvent characteristics, surface tension and evaporation rate, are found to play a role in determining uniform fiber formation with controllable diameters, degree of crystallization, and electroactive β-phase content, which are primarily responsible for the piezoelectric performance of the electrospun poly(vinylidene fluoride-trifluroethylene) P(VDF-TrFE). A substantial difference in the piezoelectric output performance is clearly observed depending on the choice of solvent. Indeed, N,N-dimethylformamide with a low evaporation rate enables piezoelectric output voltage generation of a thermally annealed P(VDF-TrFE) fiber-based device up to 139.5 V, while the device with as-spun fibers in the other solvent case, methyl ethyl ketone, yields a much lower voltage of 75.3 V. This study demonstrates that the tailoring capability of the solvent should be carefully considered together with other processing and operating conditions (e.g., thermal annealing, bending frequency, and electrical resistances) in order to realize enhanced piezoelectric energy harvesting performance of electrospun fibers for versatile potential applications.

中文翻译：

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用于增强压电能量收集的电纺 P(VDF-TrFE) 纤维中溶剂控制的结晶 β 相形成

电纺压电聚合物纤维具有机械灵活性、重量轻和相对低温处理的特点，已成为多尺度智能电子设备形状自适应能量收集和传感应用的有力解决方案。在这项工作中，我们旨在通过阐明溶剂在静电纺丝过程中的结晶动力学和纤维形成中的作用及其对收集性能的影响来提高基于电纺纤维的压电能量收集性能。发现两个关键的溶剂特性，即表面张力和蒸发速率，在确定具有可控直径、结晶度和电活性 β 相含量的均匀纤维形成中起作用，它们主要负责电纺聚（偏二氟乙烯-三氟乙烯）P（VDF-TrFE）的压电性能。根据溶剂的选择，可以清楚地观察到压电输出性能的显着差异。事实上，具有低蒸发率的 N,N-二甲基甲酰胺能够使热退火 P(VDF-TrFE) 光纤器件的压电输出电压产生高达 139.5 V，而在另一种溶剂情况下具有初纺纤维的器件，甲基乙基酮产生的电压低得多，为 75.3 V。这项研究表明，应仔细考虑溶剂的定制能力以及其他加工和操作条件（例如，热退火、弯曲频率、