单级高压微流量电渗泵的研究

设计了一种高压微流量电渗泵。泵体主要由高压电源、电渗柱、毛细通道、导电空心电极以及气泡去除器、压力传感器等构成。单级电渗泵可以给出0～20MPa范围的输出压力和nL～μL级输出流量。输出压强和输出流量取决于电压、填充柱阻力和流体性质。     

热驱动薄膜式微型泵的模拟与实验

为了了解热驱动薄膜式微型泵的性能，对泵的主要部件进行了分析，然后对泵的整体性能进行了模拟。得到了微型泵的频率特性及流量随功率的变化。发现泵的流量在 ３．３ Ｈｚ左右达到最大。膜片的预应力对泵的性能有重要影响。功率小时，预应力使流量降低，功率大时，预应力使流量增加。泵的流量与输入功率的比值与输入功率的关系曲线有最大值，约在 １．２～１．８ Ｗ之间。实验测定了微型泵的频率和功率特性，模拟结果与实测结果基本吻合。     

A numerical simulation on diffuser‐nozzle based piezoelectric micropumps with two different numerical models

This study has been conducted to compare two different numerical models for the evaluation of the performance characteristics of a diffuser‐nozzle based piezoelectric micropump. Here, the transient displacements of the membrane and the flow characteristics in the piezoelectric micropump have been closely investigated with the FSI model and the prescribed deformation model for two different frequencies. It has been found that the behaviour of the membrane computed with the FSI model is not in accordance with that with the prescribed deformation model, and that the net flow rate with the FSI model is larger than that with the prescribed deformation model. Therefore, the choice of numerical model is very important in conducting numerical analysis for piezoelectric micropumps. The results of this study can be utilized as basic data for the design and analysis of piezoelectric micropumps. Copyright © 2006 John Wiley & Sons, Ltd.     

形状记忆合金薄膜驱动微泵的动态特性

一种用形状记忆合金薄膜驱动的新型微泵已经研制成功。为了进一步提高微泵性能，研究了微泵在不同驱动条件下的动态特性。结果表明，随着驱动电流和频率的增加，驱动膜有一个最大的位移植。占空比对最大位移的影响在有无流体情况下是不同的。微泵的流量不仅仅由驱动膜的位移决定，它还与驱动频率有关。在给定的频率下，位移越大，输出流量也越大。动态驱动过程中NiTi电阻的变化表明，形状记忆合金薄膜的马氏体←→奥氏体相转变是不完全的。     

激光冲击波驱动的新型微泵数值模拟

针对传统微泵结构复杂、制备困难等不足,提出了一种新型的基于激光冲击波力学效应的微泵驱动方法,使用该方法设计的微泵结构简单、易于制造、成本低,有利于微型化及与微机电系统(MEMS)集成。通过研究激光冲击波的力学模型,设计了无阀型微泵,并计算出其耦合模态。验证了该驱动方法的可行性;通过流固耦合仿真研究了激光的频率、占空比、功率密度、光斑直径等参数对微泵流量的影响,并进一步分析了流量的稳定性。研究结果表明,功率密度和光斑直径是影响流量的主要因素,占空比为0.6时微泵流量最大,微泵稳定工作后各脉冲流量相差不超过5%。     

基于MEMS的微泵研究进展

基于微加工技术的微流体系统是微机电系统(MEMS)的一个重要分支,可广泛应用于航空航天、生物、医学、化工、电子等领域。本文主要综述了微流体系统中的微型泵结构、工作原理以及国内外研究现状。     

镍钛合金形状记忆薄膜的化学刻蚀

镍钛合金形状记忆薄膜的图形化技术曾是其实用化的主要障碍之一,现在,一种工作性能优越的化学刻蚀液可以实现薄膜的高精度图形化,该刻蚀液常温工作,性能稳定,刻蚀速率在１～５ 微米／分之间均可得到满意的刻蚀线条。常规制作的光刻胶掩模在该刻蚀液中非常稳定。该刻蚀液用于溅射态的形状记忆合金薄膜可得到与掩模图形完全一致的刻蚀结果,刻蚀线条光滑平直,刻蚀系数大于 １５。当用于热处理以后的薄膜时,刻蚀面有一定程度的粗糙化,只能用于刻蚀相对较粗的线条,这是热处理后薄膜中晶粒与晶界刻蚀速率不同所致。用该刻蚀液图形化的形状记忆合金薄膜驱动机构已成功用于微泵制造,所制作的微泵流量达到 ２００ 微升／分钟以上。     

压电微泵驱动信号及流量影响因素分析

压电微泵的泵出流量由微泵结构、压电振子特性及驱动系统驱动信号的形式决定。在机械结构及材料特性确定的条件下,压电振子的驱动信号决定着微泵输出微流量的可靠性和稳定性。在分析压电微泵驱动基理的基础上,通过Ansys对驱动压电振子有效振动的一、二阶频率进行有限元模拟分析,确定了驱动信号电压幅值、频率对微泵流量的影响。以此为基础搭建压电微泵流量测试实验平台,在相同电压和频率条件下,研究了3种不同脉冲信号（正弦波、三角波、矩形波）对输出流量的影响。通过实验对理论模型进行修正,得到了压电微泵输出流量简化模型。实验验证了所得模型在正弦波、三角波、矩形波3种不同波形驱动下最大误差不超过4%,控制范围内可靠性在99.0%以上。综合比较可知,方波脉冲信号为压电微泵最佳驱动信号。     

Electrokinetic injection of samples into a short electrophoretic capillary controlled by piezoelectric micropumps

Electrokinetic sample injection using two piezoelectric micropumps has been proposed for electrophoresis in short capillaries. The sample is brought to the injection end of the capillary using one of them. Then, the high‐voltage source is turned on and the sample is injected electrokinetically for a defined time. The injection is terminated by removal of the sample zone by the flowing separation electrolyte pumped by the second piezoelectric micropump. The RSD value, expressing the repeatability of the injection, does not exceed 4%. The injection apparatus does not contain any mobile mechanical components, there is no movement of the capillary and both its ends remain constantly in the solution during both the sample injection and separation. Thus, the micropumps replace the six‐way injection valve and linear pump in similar types of injection apparatuses. The injection was tested in the separation and determination of ammonium and potassium ions in two samples of mineral fertilizers. The separation was performed in background electrolyte containing 500 mM of acetic acid + 20 mM Tris + 2 mM 18‐crown‐6 (pH 3.3) in a capillary with id 50 μm and total length/length to the contactless conductivity detector of 10.5/8 cm. The injection and separation took place at a voltage of 5 kV and the separation time equaled 20 s. The measured values of the analyte contents corresponded to the value declared by the manufacturer within the reliability interval, where RSD equaled between 3.5 and 4.7%.     

电磁驱动柔性振动膜无阀微泵

提出了一种新型微泵设计方案和制作工艺，将电磁驱动器与大振幅振动膜相结合，得到流量大、易于控制的新型微泵。该微泵结构简单，由硅橡胶(聚二甲基硅氧烷PDMS橡胶)振动膜和无阀泵泵体组成，将硅加工工艺和非硅加工工艺(电镀)相结合。采用电镀和硅橡胶加工方法将振动膜直接制作在一个硅片上；用电镀和体硅加工工艺将驱动线圈和无阀泵泵体制作在另一块硅片上，然后将两个硅片键合在一起。对该微泵的性能特点正进行着更深入的研究。