Development of an electrohydrodynamic injection micropump and its potential application in pumping fluids in cryogenic cooling systems
Development of an electrohydrodynamic injection micropump and its potential application in pumping fluids in cryogenic cooling systems
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DOI：
10.1109/jmems.2005.845413
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发表时间：
2005-08-01
影响因子：
2.7
通讯作者：
Wang, HX
中科院分区：
文献类型：
--
作者：
Darabi, J;Wang, HX
低温冷却已成为提高电子设备和传感器性能的一种广泛采用的技术。电流体动力(EHD)泵系统的一个潜在应用是用于低温冷却系统中的流体泵送。在本文中，我们给出了理论和实验研究的结果，以研究使用EHD注入微泵泵送液氮的可行性。首先，讨论了低温液体中电荷输运和电离现象的机理。然后，介绍了一种采用交叉型锯齿/平面电极阵列的EHD注入微泵的设计和制造。最后给出了实验结果和观察结果。设计了一种非对称的锯齿/平面几何结构，以获得较强的非均匀电场。每个发射极电极的底部宽度为10微米，发射电极上的每个牙齿的底部长度为10微米，尖端角度为60度。集电极由一条宽度为10Pro的平面条组成。发射极和集电极之间的距离为20微米。每个相邻阶段(一对发射极和集电极)之间的距离为40 pm图案化面积为10 mm×20朗姆，允许沿着微泵长度制造大约200个阶段。在没有净流量的情况下，该微泵对3M的HFE-7100热流体和液氮的最大压头分别为550和205Pa.此外，在用HFE-7100进行的闭环测试中，在180帕的产生压力下，最大质量流速为3.9g/min。
Cryogenic cooling has become a widely adopted technique to improve the performance of electronics and sensors. A potential application of an electrohydrodynamic (EHD) pumping system is its use in pumping fluids in cryogenic cooling systems. In this paper, we present the results of a theoretical/experimental investigation to study the feasibility of using an EHD injection micropump for pumping liquid nitrogen. First, the mechanisms of charge transport and ionization phenomenon in cryogenic liquids are discussed. Next, the design and fabrication of an EHD injection micropump that employs an array of interdigitated saw-tooth/plane electrodes are described. Finally, experimental results and observations are presented. An asymmetric saw-tooth/plane geometry was designed to achieve a strong inhomogeneous electric field. Each emitter electrode had a base width of 10 mu m. Each tooth on the emitter electrode had a base length of 10 mu m with a tip angle of 60 degrees. The collector electrode consisted of a planar strip with a width of 10 pro. The gap between emitter and collector electrodes was 20 mu m. The distance between each neighboring stage (a pair of emitter and collector electrodes) was 40 pm. The patterned area was 10 mm by 20 rum allowing approximately 200 stages to be fabricated along the length of the micropump. The maximum pressure head achieved by this micropump in the absence of a net flow was 550 and 205 Pa for 3M's HFE-7100 thermal fluid and liquid nitrogen, respectively. Also, the maximum mass flow rate was 3.9 g/min at the generated pressure of 180 Pa during a closed loop test with HFE-7100.[1063].