基于近场静电纺丝的驻极化聚合物MEMS结构在线制备机理研究

Electret polymer-based MEMS structures have great application potential in the field of flexible micro/nano devices, attributed to the merits of flexibility, light weight, and inherent electrostatic effect, etc. Utilizing polymeric electret materials as the precursor solution, through the fiber-by-fiber stacking, this project proposes an in-situ fabrication technique for a novel electret polymer-based MEMS structures based on the high electric field during near-field electrospinning, including: the in-situ injection mechanism of charges into precursor during near-field electrospinning is studied, establishing the theoretical model. The micro-structure, surface potential, energy level distribution and energy depth of traps for the near-field electrospun fibers are characterized and analyzed, establishing the internal relationship between processing parameters and electret property. Then, the dynamic attenuation characteristics of electret charges is monitored, ascertaining the escape mechanism of electret charges, and proposing effective methods to shield the attenuation. Finally, various of structures-controllable, high aspect-ratio electret polymer-based MEMS structures are fabricated, realizing the efficient acquisition and transformation of electrostatic energy, and effective electrostatic assembly of electrochemically active materials. The purpose of this project is to reveal the mechanism and basic rules of in-situ electret poling of near field electrospinning, truly realize an integrated process for the fabrication of polymer-based MEMS structures and the high efficiency of electret poling, Further understand the behavior of the electret charges. As such, it is of great theoretical significance and practical value.

具有驻极功能的聚合物MEMS结构以其柔性、质轻、固有的静电效应等优点，在柔性微纳器件领域具备广阔的应用前景。本项目基于近场静电纺丝的强电场作用，以聚合物驻极体配制前驱液，通过控制纤维的一致性重复堆叠，提出一类新型驻极化聚合物MEMS结构的在线制备方法，主要包括：研究近场静电纺丝过程中电荷的原位注入机制，建立在线驻极理论模型，表征分析纤维的微观结构、表面电位、陷阱能级分布与能势深度等，构建工艺参数与驻极性能的内在关系；监测驻极电荷后续的动态衰减特性，探明驻极电荷的脱阱机制，提出有效的防护驻极电荷衰减的工艺方法；制备形状可控、高深宽比的驻极化聚合物MEMS结构，实现静电能量的高效获取与转换、电化学活性材料的静电装载。本项目旨在揭示近场静电纺丝的在线驻极机理与基本规律，实现聚合物MEMS结构制备与高效驻极化的一体化工艺，进一步加深对驻极电荷行为特征的理解，具有十分重要的理论意义和实用价值。

具有驻极功能的聚合物MEMS结构以其柔性、质轻、固有的静电效应和压电效应等优点，在柔性微纳器件领域具备广阔的应用前景。然而，现目前的驻极化聚合物MEMS制备工艺复杂、成本高昂，限制了其应用拓展。本项目基于近场静电纺丝的强电场和静电拉伸作用，以聚合物驻极体配制前驱液，通过控制纤维的一致性重复堆叠，提出了一类新型驻极化聚合物MEMS结构的在线制备方法，主要完成了以下工作：研究了近场静电纺丝过程中电荷的原位注入机制，建立了单极电荷注入、电晕电荷注入的在线驻极理论模型；通过SEM、EFM、静电计表征分析了纤维的微观结构、表面电位；监测了驻极电荷后续的动态衰减特性，通过掺杂无机二氧化硅纳米颗粒提升了驻极性能稳定性；制备了多种形状可控的驻极化聚合物MEMS结构，深宽比达到40:1以上，基于压电效应和静电效应实现了能量的高效获取与转换，并研制了相应的可穿戴力学传感器。本项目提出了一类新机理，开发了一类新工艺，基于该类驻极功能结构的一体化制造特点，体现出工艺简易、结构简单、柔性可靠等特点，在柔性电子、可穿戴能量收集与传感等领域具有应用前景。