聚合物喷针纳米通道中电液动力射流体尺度效应的研究

The electrohydrodynamic jet printing is a low-cost, high-resolution, and direct write-on-demand nanofabrication technique. To further improve the resolution of electrohydrodynamic jet printing, it is important to study the nano size effect of electrohydrodynamic jet flow. Within the term of this proposal there are three research contents: 1 The space-charge in the electrical double layer at the liquid-solid interface varies with the channel size. The influence of the channel size and space-charge on the ion enrichment concentration and generation rate will be investigated to identify the relationship between the enrichment ions Coulomb repulsion and the liquid surface tension on the liquid-gas interface meniscus. The relative position of the slip plane on the liquid-solid interface changes with channel size as well. The effect on the channel size and slip plane on the extent of the boundary slip will be studied to clarify the flow characteristics of electrohydrodynamic jet fluid both inside and outside of the nanochannel. 2 To optimize the processing parameters of thermal nanoimprint, generalized Maxwell viscoelastic high-order parametric model of the thermal nanoimprint will be established and the influence of the polymer creep and stress relaxation on replication accuracy will be studied. 3 An approach based on sputtering etch will be examined to reduce the fabrication cost and improve precision of the 2D nano-mold fabrication. Polymer electrohydrodynamic jet emitter will be fabricated by using the UV lithography and thermal nanoimprint. The emitter channel is made from micro-nano composite structures in which the dimension of the nanochannel is less than 100nm. Finally, an electrohydrodynamic jet printing system will be build up with super low-cost, high-resolution, and direct- write-on-demand. This proposed work will provide a flexible, simple, low-cost, and practical nano-fabrication method for the nano-science research.

电液动力射流打印是一种低成本高分辨率按需直写的纳米制造技术。为进步提高电液动力射流打印分辨率，本项目开展电液动力射流体纳米尺度效应研究：1分析液固界面双电层空间电荷随通道尺度变化对离子富集浓度及速率的影响，明确富集离子库伦斥力在液气界面弯液面内与液体表面张力相互作用机理；分析液固界面滑移层相对位置随通道尺度变化对边界滑移程度的影响，明确电液动力流体在纳米通道内部及外部的流动特性。2建立适用于热纳米压印过程的广义Maxwell粘弹性高阶参数模型，明确聚合物蠕变松弛特性与复制精度的对应关系，以优化热纳米压印工艺参数。3采用离子溅射刻蚀制造低成本高精度二维纳米模具。采用热纳米压印结合紫外光刻制造聚合物喷针，喷针内壁由微纳复合结构组成，其中纳米通道尺度控制在100nm以下。最终建立起超低成本高分辨率电液动力射流按需直写打印系统。研究成果将为纳米科学研究提供一种灵活简单低成本实用性的纳米制造方法。

电液动力射流打印是一种高分辨率、高精度和低成本的按需直写纳米制造技术。为了研究电液动力射流纳米尺度效应及提高电液动力射流打印分辨率，深入分析了聚合物材料特性与复制精度的对应关系，设计并优化了多种两维纳米硅模具和聚合物喷针制造工艺。最终制造了100 nm以下和50 nm以下的低成本高精度二维纳米模具。利用二维纳米硅模具，采用紫外曝光与热纳米压印相结合的方法以及双注法制造了SU-8和PDMS聚合物喷针。喷针内壁由微纳复合结构组成，其中纳米通道尺度控制在100 nm以下。建立了低成本高分辨率电液动力射流按需直写打印系统。深入研究了电液动力射流打印特性，构建了电液动力射流仿真模型，分析了液固界面双电层空间电荷及富集离子库伦斥力在液气界面弯液面内与液体表面张力相互作用机理，明确了电液动力流体在微纳通道内部及外部的流动特性，分析了喷针尺寸、喷针角度、电压、墨水密度、液滴所带的电荷数量对电场密度、液滴速度和液滴沉积方向的影响。进行了微纳尺度喷针电液动力射流打印实验，优化了打印工艺参数，实现了PZT溶胶凝胶、纳米银颗粒和聚氧化乙烯（PEO）的纳米图形直写打印，最小线宽低至70 nm。项目研究成果将对纳米尺度结构直写和微纳米器件的制造具有重要意义和参考价值，为纳米科学研究提供了一种灵活简单低成本实用性的纳米制造方法。