To control the velocity and one-way flow of fluid in a micro-fluidic system, a novel passive micro-valve was designed base on Micro-electrical-mechanical System (MEMS) technology. By drawing lessons from a human heart valve structure, the deflections and stresses of a valve membrane under different pressures were analyzed with ANSYS by using SU-8 as the passive micro-valve structural materials, then the thickness of the valve membrane was optimized. The valve was fabricated with integrated processing of MEMS technique, so that the process technology for the valve membrane was determined. The performance of the passive valve was tested using deionized water as media and the forward flow velocities obtained are 1. 66 ml/min for type A and 1. 35 ml/min for type B under a forward pressure of 11. 7 kPa. The tested analyzing data indicate that the designed passive valve has the potentiality of linear control, which means that the passive micro-valve made by SU-8 has not only better performance but also better bio-compatibility and can extend the applications of passive micro-valves.%为了在微流体控制系统中实现对流体流速的控制和流体的单向流动,借鉴人体心脏瓣膜的结构,设计了新型被动式微阀.选用SU-8作为被动式微型阀的结构材料,用ANSYS仿真了不同厚度(10,15,20 μm)的阀门膜片在不同压力作用下的挠度与应力,进而确定了合适的阀门膜片厚度.利用微细加工技术,集成加工了微型阀,并由此确定和优化了微型阀的加工工艺.用去离子水作为介质测试了微型阀的过流特性,在正向压力为11.7 kPa的压力作用下,测得A、B型被动式微阀的正向流速分别为1.66 ml/min和1.35 ml/min.对测试数据的分析表明,设计的微型阀有线性控制的潜能.以SU-8胶作为结构材料的微型阀不仅性能较好,同时具有生物兼容性,可扩展微型阀的应用范围.
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