Fabrication Process Optimization And Output Performance Research On Electro-Conjugate Fluid Micropump

The electro-conjugate fluid (ECF) micropump is novel fluid machinery, which takes ECFs as working fluid and transfers electric power to kinetic energy of fluid without any mechanical motion based on ECF effect. It features simple structure, high efficiency of energy conversion, high power density ratio as well as low noise. As the core part of the micropump, ECF jet generator applies triangular-prism slit (TPS) electrode pair (thickness of 500um and aspect ratio of over 2.5) structure and is fabricated based on MEMS technology (evaporation, UV-LIGA, et al). In order to improve manufacture accuracy of the jet generator, optimize dimensional parameters of TPS electrode pairs array and enhance output performance of the ECF micropump, the research works of this paper are as follows:(1) Improvement of MEMS based manufacturing process for jet generator. Through several means including nickel electroplating on the conductor layer, RIE process before electrode electroforming, change of process parameter of photoresist spin coating, heat treatment and removal method, and shape optimization of slit electrode, the attachment rate of slit electrodes has been improved and the structural defect on the tip of the triangular-prism electrodes has been solved. Finally, the whole MEMS fabrication procedure which fabricates jet generators with 500μm thickness and aspect ratio over 2.5 of electrode is improved to assure its accuracy and intact rate.(2) Dimensional parameters optimization of TPS electrode pairs array. Based on the experience of optimization of single TPS electrode pair with millimeter feature size, optimization of the TPS electrode pairs array with several hundred microns feature size is completed. The output performance comparative experiments of ECF micropump based on single factor experiment method is utilized to study the influence of every dimensional parameter on its output performance. In addition, the analysis and verification of experiment result is given based on pumping principle of ECF effect.(3) Design of improved ECF jet generator with bypass micro-channel. In order to solve the pressure-drop problem of ECF jet generator when its output flow is small, theoretical analysis of the influence of small output flow rate on the ECF effect strength is given based on the principles of ion drag and conduction pumping. The improved jet generator with bypass micro-channel is presented to enhance output performance of the ECF micropump. Finally, output performance comparative experiment is conducted to verify its feasibility.This research related to ECF micropump is researched at the first time in China. According to theoretical analysis and experimental research, several essential points about fabrication technology, dimensional design and output performance of the ECF micropump are solved. The research of ECF micropump and applications based on ECF effect are carried forward by this project.