基于硅尖浸润聚焦的纳米分辨率电射流打印研究

Electrohydrodynamic jet (E-jet) printing is a promising technique for micro-nano manufacturing due to its advantages such as high-resolution deposition, wide material adaptability, high efficiency and environment friendliness. To date, the highest resolution of sub-micrometric scale has been reported for E-jet printing based on the traditional Taylor-cone focusing mechanism, which has closed to the physical limits of this kind of E-jet printing. To break through this resolution limit and further improve it to nano scale, a new method for nano-resolution E-jet printing based on the mechanism of wetting-driven liquid focusing on a silicon tip is presented in this project application. By using the theory of nano-fluid dynamics and molecular dynamics, the process of liquid film infiltration and droplet focusing on the silicon tip surface will be studied, and the formation, controlling and ejection methods for attoliter liquid droplets produced from the focusing nano silicon tip will also be investigated. The drop-on-demand E-jet printing by using silicon tip focusing can be achieved from the above-mentioned studies. There is no similar research works have been reported hitherto. Results from this project can be expect to provide a new view on the infiltration process on solid-liquid interface in nano structure, and develop technology architecture for nano-resolution E-jet printing.

电射流打印具有沉积精度高、材料适应性广、工艺高效环保等优点，在微纳制造领域有广阔的应用前景。目前，基于泰勒锥电流体动力聚焦原理的电射流打印最高分辨率已达到亚微米量级，接近现有电射流聚焦方法的物理极限。为突破这一分辨率极限并将电射流打印分辨率进一步提升至纳米尺度，本项目提出基于硅尖表面浸润聚焦机理的电射流纳米打印新方法；结合纳米流体动力学和分子动力学理论, 研究纳米尺度下硅尖表面的液膜浸润及液滴聚焦机制，探明基于纳尺度硅尖浸润聚焦的阿升级液滴的形成规律与操控方法, 获得纳米尺度下硅尖聚焦和液滴发射过程的电流体动力学控制规律, 实现对纳米液滴的电射流按需打印。目前国内外尚未有同类研究的报道。项目成果将在科学层面上扩展人们对纳尺度结构固液界面浸润过程和规律的认知，在工程应用上发展出纳米分辨率的电射流打印技术体系，推动电射流打印技术和装备的新发展。

电射流打印具有沉积精度高、材料适应性广、工艺高效环保等优点，在微纳制造领域有广阔的应用前景。目前，基于泰勒锥电流体动力聚焦原理的电射流打印最高分辨率已达到亚微米量级，接近现有电射流聚焦方法的物理极限。为突破这一分辨率极限并将电射流打印分辨率进一步提升至纳米尺度，本项目提出了基于尖端表面浸润聚焦的纳米电射流打印新原理，建立了纳米尺度下聚焦尖端毛细-静电协同浸润效应对固液界面运动演化的数理模型，确立了尖端聚焦纳米液滴脉冲电射流打印过程的电流体动力控制方程，探明了打印结构参数、打印驱动参数和墨水物性参数对打印性能的影响规律，发展出聚焦尖端上纳米液滴逐点可控、按需打印的新方法，研制出一套尖端聚焦纳米分辨率电射流打印装置样机，其打印范围≥1000μm×1000μm，纳米点打印分辨率达70nm，纳米线打印分辨率达30nm，为新一代高性能纳米器件的高精、高效制造提供了有力的新工具和新方法。在项目资助下，共发表学术论文17篇，其中SCI收录7篇（含IF6.0以上3篇），EI收录2 篇，授权国家发明专利2项，申请美国发明专利2项，培养博士研究生3人，硕士研究生17人（毕业13人）