用微芯片化学反应器实现酶催化化学发光测定葡萄糖的研究

葡萄糖是临床化学诊断以及食品分析中重要的检测项目 ,最常用的测定方法是采用葡萄糖氧化酶(GOD)催化葡萄糖与氧分子间反应 ,生成葡萄糖酸和过氧化氢 [1] ,而对过氧化氢的检测则可采用过氧化酶 (POD)催化鲁米诺的化学发光反应进行 [2 ] .FIA对整个过程的实现是十分有效的方式 ,但由于多采用固定化酶反应器 [3～ 5] 使其在制备及分析上较复杂且费用高 .由 Manz等[6] 提出的微型全分析系统(μ- TAS)在针对不同体系的微量分析及在线监测上均具有突出的优越性 .本文使用的含微混合器的微芯片化学反应器采用μ- TAS设计思想 ,建立了化学发…     

A novel 3D Tesla valve micromixer for efficient mixing and chitosan nanoparticle production

Current three-dimensional micromixers for continuous flow reactions and nanoparticle synthesis are complex in structure and difficult to fabricate. This paper investigates the design, fabrication, and characterization of a novel micromixer that uses a simple spatial Tesla valve design to achieve efficient mixing of multiple solutions. The flow characteristics and mixing efficiencies of our Tesla valve micromixer are investigated using a combination of numerical simulations and experiments. The results show that in a wide range of flow rates, viscoelastic solutions with different concentrations can be well mixed in our micromixer. Finally, experiments on the synthesis of chitosan nanoparticles are conducted to verify the practicability of our micromixer. Compared with nanoparticles prepared by conventional magnetic stirring, the size of nanoparticles prepared by micromixing is smaller and the distribution is more uniform. Therefore, our Tesla valve micromixer has significant advantages and implications for mixing chemical and biological reactions.     

Tesla微混合器结构参数对混合强度的影响

针对Tesla微混合器混合原理,利用计算流体力学(CFD)模拟与分析软件对其进行了三维数值模拟.模型采用有限体积法离散、SIMPLEC算法进行层流计算.分析了结构参数的改变对该混合器混合效果的影响,并采用混合强度值作为衡量指标.分析结果显示,不同通道高宽比和分离通道入流角度等结构参数对该微混合器的混合效果有重要影响.模...     

Polymer micromixers bonded to thermoplastic films combining soft‐lithography with plasma and aptes treatment processes

Over the past few years, a growing interest on covalent bonding of polydimethylsiloxane (PDMS) microfluidic devices to thermoplastic films has developed due to reduced costs, biocompatibility, and flexibility. The silane reagent, 3‐aminopropyltriethoxysilane (APTES) has been applied to create this bonding. Here, we report on the fabrication of replica PDMS micromixer devices from a silicon mold using soft lithography that is rapid, facile, and cost‐effective to manufacture. After replica molding, the PDMS micromixer devices were bonded to the APTES‐activated thermoplastic films of polyimide, polyethylene terephthalate, and polyethylene naphthalate. Characterization of these thermoplastic surfaces was analyzed by contact angle measurement, surface free energy, and X‐ray photoelectron spectroscopy. To demonstrate the functionality of this technology, we have analyzed the PDMS micromixers by a peel test, nonleakages, and mixing with the injection of inks, a surfactant, and varying pH solutions. To our knowledge, this is the first reported example in literature of the PDMS–APTES–thermoplastic films preparation that integrates a complex micromixer device. Here, we have established that the hydrophobicity of both sealed polymers required alteration in order for dispersion of a polar liquid in the mixing loops. The application of a polar solvent before injection can remedy this ill effect formulating a hydrophilic micromixer. These preliminary results demonstrate the feasibility of the fabrication technology, bonding technique, and application of the micromixer that, once optimized, can eventually integrate more components to formulate a lab‐on‐a‐chip with the fabrication of gold microelectrodes for biological analysis of blood or plasma. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

带有微混合器的固定床反应器中的环己烯水合反应

 在固定床反应器中考察了环己烯水合反应,同时采用一种新型微混合器促进油水两相的混合. 结果表明,该微混合器用于环己烯和水反应时可极大地促进环己烯和水的混合,并进而促进水合反应的进行. 环己烯转化率和环己醇选择性分别达到9%和99%, 同时反应时间缩短至0.3 h.     

Microfabricated devices for fluid mixing and their application for chemical synthesis

Over the last few decades, the processes of miniaturization, integration, and automation have revolutionized the world of science and industry. Within a chemical reaction process the unit operations, mixing, heating, and cooling, can be regarded as key steps. In microreactors, enhanced heat and mass transport, due to small characteristic dimensions together with large surface to volume ratios, are expected to open up a whole range of new possibilities. Increase in reaction yield, reduction of reaction time as well as byproduct formation, inherent process safety, and even completely new process routes are some of the advantages associated with microTAS (micro Total Analysis Systems) or microSYNTAS (micro SYNthesis Total Analysis Systems). This article aims to describe the development of microfabricated devices for fluid mixing, so-called micromixers, and their application for chemical synthesis.     

Design and Fabrication of a Three Dimensional Spiral Micromixer

In this work, we present a three dimensional micromixer which consists of two layers of spiral channels overlapped together in the vertical direction. This micromixer is designed by using a smooth channel twisted into double‐layer spiral geometry with simple topological structure. Based on the principle of Dean effects, this kind of structure is beneficial to produce, enhance and sustain the Dean vortices, which can perturb the laminar fluid effectively. In order to improve the mixing performance, the detailed parameters have been optimized by using the computational fluid dynamics software. The results indicate that the erect channel which is connected with the two layers of spiral channels plays a critical role for well mixing. Meanwhile, the effect of mixing has been identified in a fabricated glass‐micromixer. The mixing ef?ciency of 90% has been achieved by optimizing the flow rate and the structure of the erect channel. Thus, this micromixer has manifested high mixing efficiency and presents good practicability in the versatile microfluidic systems.     

Development of a passive micromixer based on repeated fluid twisting and flattening,and its application to DNA purification

We have developed a three-dimensional passive micromixer based on new mixing principles, fluid twisting and flattening. This micromixer is constructed by repeating two microchannel segments, a “main channel” and a “flattened channel”, which are very different in size and are arranged perpendicularly. At the intersection of these segments the fluid inside the micromixer is twisted and then, in the flattened channel, the diffusion length is greatly reduced, achieving high mixing efficiency. Several types of micromixer were fabricated and the effect of microchannel geometry on mixing performance was evaluated. We also integrated this micromixer with a miniaturized DNA purification device, in which the concentration of the buffer solution could be rapidly changed, to perform DNA purification based on solid-phase extraction.     

Visualization and Analysis of a Micro-Flow Generated by an Optical Rotator

Micro-flow control is the key technology of the so-called labs-on-a-chip fluidic devices such as micro total analysis systems (μ-TAS). This letter presents a micro-flow generated by a broken glass particle rotation induced by optical pressure. The micro-flow fields are visualized by both tracer and optical methods. The velocity vectors are analyzed for the future evaluation of the micro-mixing.     

A three-dimensional vortex microsystem designed and fabricated for controllable mixing

A three-dimensional micromixer is designed and fabricated by using glass-poly(dimethylsiloxane) (PDMS) hybridized materials. The improvement of the fabrication process makes the micromixer endure much higher flow rate. Based on the self-rotation effect of the fluid, the fast mixing can be achieved. The mixing process is evaluated by connecting the micromixer to a UV-Vis detector. The results show that by adjusting the infuse flow rate, the mixing process can be accurately controlled. Supported by the National Natural Science Foundation of China (Grant Nos. 20735002 & 29877019) and the Key Natural Science Foundation of Fujian Province, China (Grant No. D0520001)