微流体驱动与控制系统的研究进展北大核心

随着微流控系统的应用越来越广泛,微米尺度和纳米尺度器件微通道内的流动逐渐成为了研究的热点。重点阐述了微流控系统的驱动元件——微泵、控制元件——微阀的研究现状,介绍了学者们研制的各种微泵、微阀的工作原理与结构特点,指出了微流体驱动控制系统泄漏、结构复杂、成本偏高等问题依然存在,并对微驱动控制的发展方向进行了展望。     

利用体块PZT制备膜片式压电微泵

利用锆钛酸铅(PZT)的逆压电效应,设计并制备了膜片式压电微泵。通过将电能转换为机械能,实现了液体的微流体控制。微泵由微驱动器与单向微阀两部分组成;微驱动器主要为液体流动提供驱动力,单向微阀则用于精确控制液体的流动方向。通过对PZT-Si膜片的位移量、位移形状的仿真分析,确定了微驱动器的设计尺寸,并估算其液体驱动性能。利用共晶键合工艺、研磨减薄工艺、硅深反应离子刻蚀工艺和准分子激光加工工艺等制备出了微驱动器和单向微阀。最后,设计了驱动测试实验,检测了微泵的液体驱动性能。测试结果表明:所制备的膜片式压电微泵驱动的谐振频率约为70kHz,能驱动微米量级的液体位移或运动。当微泵驱动电压为30Vp-p、频率为600Hz时,液体的驱动流速约为65μL/min。该微泵具有体积小,线性度好等特点。     

三齿轮微泵设计与微Logix齿轮的铣削加工

渐开线齿轮和单泵供油技术难以满足微型齿轮泵高均匀介质和低损耗的工作要求。Logix齿轮根切倾向小、易于设计成少齿数。双泵合流技术可实现流量补偿并降低流量脉动。设计了一种基于Logix齿形的三齿轮微泵结构,三齿轮泵排量仿真结果表明,基于Logix齿形的三齿轮微泵较二齿轮泵的流量脉动性能好,三齿轮泵的排量比二齿轮泵增加1倍,而排量变化幅度只有二齿轮泵的一半。计算确立了Logix齿轮的结构参数,制订了Logix齿轮的微铣削工艺,加工制造了基于Logix齿形的微齿轮泵。     

采用无阀微泵的微调焦系统特性研究

该文提出了一种由一组无阀压电微泵、调焦透镜、储液容器、位移传感器、电源和控制器等组成的微流控调焦透镜系统,介绍了该系统的结构及工作原理,建立了无阀压电微泵及系统的动态数学模型,并利用Matlab/Simulink软件,分别对单泵工作和双泵工作两种工作模式下系统的动态特性进行了仿真研究,给出了仿真结果并进行了分析。     

微通道内台阶阀截止过程中的毛细流动动态效应

分析了由亲/疏水性不同壁面组成的微通道内毛细流动的动态效应对台阶阀截止功能的影响和在台阶阀截止过程中毛细流动动态效应与台阶阀前微通道长度的关系.根据毛细被动阀的工作原理和能量守恒原理,得出台阶阀有效截止时,台阶阀前微通道临界长度的计算公式.通过数值仿真得到临界长度所对应的计算长度,当台阶阀前微通道实际长度大于等于计算长...     

基于微流控技术的新型PDMS平面微阀

针对常规微阀结构较为复杂,存在着制作成本较高、难于加工和不易系统集成等问题,提出了一种设计简单的柔性阀片-阀塞结构的PDMS平面微阀的研究.微阀的制作采用了标准PDMS模塑法微细加工工艺.测试结果表明微阀工作性能良好,反向泄漏量可以减少到0.1 mL/min,而微阀的正/反向流量比可以达到41:1,满足了微流体控制系统对流量调节的要求,可广泛应用于各种微流控系统中.     

聚酰亚胺微型阀及其加工工艺

在回顾微型阀发展并分析单晶硅微型阀和多晶硅微型阀加工工艺基础上,提出一种聚酰亚胺微型被动阀,分析聚酰亚胺的材料性能,设计微型阀结构和加工工艺流程,成功地制造出聚酰亚胺微型阀,测试该阀性能,讨论加工过程中的一些关键工艺。     

基于MEMS的微流体机械研究进展

介绍了近十年特别是近三年以来微流动系统研究的最新成果，具体介绍了新型微加速度计、微泵、微喷、微阀、微通道及微系统的结构、原理及应用情况，并对微流动系统研究中存在的问题和发展方向作了简述。     

一种新型电磁驱动微泵的设计与制作工艺

主要阐述了一种新型电磁驱动微泵的设计和制作工艺。该微泵结构简单，由驱动线圈、硅橡胶振动膜和无阀泵泵体组成，采用硅加工工艺和非硅加工工艺(电镀)相结合进行制作。采用模压法和硅橡胶加工方法将振动膜直接做在一个硅片上；用电镀和硅体加工工艺制作驱动线圈和无阀泵泵体，然后将3个基片键合在一起。     

电流变技术在微型机械系统中的应用研究

介绍了电流变技术在微型机械系统中的应用，特别介绍了三通口微型电流变阀的结构特点，制造工艺，基本特性，并通过实验模型阐述了这种阀的可行性。     

Piezoelectric diffuser/nozzle micropump with double pump chambers

To eliminate check valve fatigue and valve clogging, diffuser/nozzle elements are used for flow rectification in a valveless diffuser/nozzle micropump instead of valves. However, the application of this type of micropump is restricted because of its pulsating or periodic flow and low pump flux. In this paper, a diffuser/nozzle Si/Glass micropump with two pump chambers by IC and MEMS technology is designed. The fabrication process requires only one mask and one etch step, so that the fabrication has the advantages of low cost, short processing period, and facilitation of miniaturization. The pump is equipped with a glass cover board so as to conveniently observe the flow status. Pump-chambers and diffuser elements are fabricated by the anisotropic KOH-etch technique on the silicone substrate, and the convex corner is designed to compensate for an anisotropic etch. The driving force of the micropump is produced by the PZT piezoelectric actuator. The pump performance with both actuators actuated in anti-or same-phase mode is also researched. The result indicates that the micropump achieves great performance with the actuators working at anti-phase. This may be because the liquid flows steadily, pulse phenomenon is very weak, and the optimal working frequency, pump back pressure, and flow rate are both double that of the pump driven in same-phase.     

Piezoelectric diffuser/nozzle micropump with double pump chambers

To eliminate check valve fatigue and valve clogging, diffuser/nozzle elements are used for flow rectification in a valveless diffuser/nozzle micropump instead of valves. However, the application of this type of micropump is restricted because of its pulsating or periodic flow and low pump flux. In this paper, a diffuser/nozzle Si/Glass micropump with two pump chambers by IC and MEMS technology is designed. The fabrication process requires only one mask and one etch step, so that the fabrication has the advantages of low cost, short processing period, and facilitation of miniaturization. The pump is equipped with a glass cover board so as to conveniently observe the flow status. Pump-chambers and diffuser elements are fabricated by the anisotropic KOH-etch technique on the silicone substrate, and the convex corner is designed to compensate for an anisotropic etch. The driving force of the micropump is produced by the PZT piezoelectric actuator. The pump performance with both actuators actuated in anti- or same-phase mode is also researched. The result indicates that the micropump achieves great performance with the actuators working at anti-phase. This may be because the liquid flows steadily, pulse phenomenon is very weak, and the optimal working frequency, pump back pressure, and flow rate are both double that of the pump driven in same-phase.     

悬臂式微型压电泵的试验研究

利用压电晶片致动式压电泵的工作原理,提出一种整机采用迭片式结构,单向阀采用悬臂式薄片阀的新结构微型压电泵,设计、制作了试验样机,并对该泵的工作性能进行了较为系统的试验测试和研究。通过试验测试：该泵工作性能稳定,整机具有较高的体积功能比。该泵设计方法及制作工艺对研发适于大量生产的实用微型泵是一个有益的尝试。     

Fabrication and evaluation of various types of micro one-way valves through micro rubber molding process

In recent years, research and development on micro fluid systems has become active in the fields of chemical technology and biotechnology. For the realization of these micro fluid systems, micro fluid devices such as micro-valves and micro pumps are very important. This paper reports the fabrication and experimental evaluation of several micro one-way valves. The valves are fabricated through a micro molding process, which makes the fabrication process simple and suitable for mass production. The experimental results indicate that the developed valve has great performance with a normal flow rate of 130.2 ml/min and a leak flow of 2.2 ml/min. The normal flow rate is 1.4 times higher than that of the previous model.     

An active manufacturing method of surface micro structure based on ordered grinding wheel and ultrasonic-assisted grinding

At present, many studies have shown that crosshatch micro structures can effectively improve surface performance. This paper presents a method for manufacturing micro structure based on ultrasonic-assisted grinding (UAG) and ordered grinding wheel. Firstly, the parameters of ordered grinding wheel and the surface characteristic parameters in relation to working performance are proposed. According to the kinematics of grinding, the governing equation between the surface characteristic parameters and the machining parameters is established. Based on the proposed characteristic parameters, the pattern parameters and machining parameters are inversely solved by the governing equation. The crosshatch micro structure manufacturing based on ordered grinding wheel and ultrasonic-assisted grinding is achieved, and because the fabrication technology of the grinding wheel is not mature, its correctness and feasibility are preliminary verified by the numerical simulation method and grinding experiment. The paper method is original for the active manufacturing of the crosshatch micro structure and is of reference value for the micro structure active manufacturing.     

聚二甲基硅氧烷气动微型蠕动泵制作工艺的研究

聚二甲基硅氧烷(PDMS)气动微型泵由3个PDMS气动微阀构成,依靠3个微阀的蠕动作用实现输运液体的作用.PDMS气动微泵的关键制作工艺是液体通道的弧形化和PDMS层之间、PDMS层与玻璃基片之间的封接.实验证明AZ4620正性光刻胶所制作的阳模能形成剖面形状呈弧形的液体通道.采用等离子体氧化处理法封接技术实现了PDMS层之间、PDMS层与玻璃基片之间的封接,该工艺易操作,封接速度快,而且封接效果好.     

Micro press forming and assembling of micro parts in a progressive die

A micro press forming and in-process assembly technology were developed and applied to fabrication of metal parts and units. Technologies based on high-energy beams, such as ion and short pulse laser were developed for fabrication of features of dies in micro scale and finishing surface in nano scale. In addition, DLC coating on surface of the die was developed in order to improve wear-resistance and reduce friction. A micro gear with diameter of 0.2 mm was produced using sheet metals. Furthermore, a unit part with three components was fabricated in a precise progressive die using the micro press system. The results show that the micro metal forming could be a new technology for fabrication of micro devices, such as MEMS, bio-chips in low cost and with large quantities.     

Fabrication and drive test of a peristaltic thermopnumatic PDMS micropump

This paper presenti, fabrication and drive test of a peristaltic PDMS micropump actuated by the thermopneumatic force The micropump consists of the three peristaltic-type actuator chambers with microheaters on the glass substrate and a microchannel connecting the chambers and the inlet/outlet port The micropump is fabricated by the spin-coating process, the two-step curing process, the JSR (negative PR) molding process, and etc The diameter and the thickness of the actuator diaphragm are 2 5 mm and 30 μm, respectively The meniscus motion in the capillary tube is observed with a video camera and the flow rate of the micro pump is calculated through the frame analysis of the recorded video data. The maximum flow rate of the micropump is about 0 36 μL/sec at 2 Hz for the zero hydraulic pressure difference when the 3-phase input voltage is 20 V.     

硅微热致动泵的关键加工工艺

提出了一种新型结构的硅微热致动泵,对该泵相关的微机械关键加工工艺进行了综述分析和试验研究。     

NiTi/Si薄膜驱动微型无阀泵的系统研究

介绍了形状记忆合金 /硅 (Ni Ti/Si)复合膜驱动的微型无阀泵的结构及工作原理 ,采用 Matlab对微泵的压力 P和流量 Q进行了计算和仿真 ,并将仿真结果与实验结果进行了对比。通过分析驱动膜的驱动频率与泵的几何结构对微泵性能的影响 ,得到微泵的优化方案。