用于食品安全检测的声表面波微流控系统研究

In order to improve the performance of micro-mixing and food detection in micro-fluidic system, we intend to exploit a new flow injection micro-fluidic system, which is consisted of Surface-Acoustic-Wave device, intelligent temperature control device and micro-channel. In this project, we take aflatoxin detection as an example to verify the micro-flow mixing effect. We hope that the micro-fluidic system will offer an easy and fast method for food safety testing. First, we will study the interaction effect of the sound field, electric field, thermal field and micro-fluid in the micro-environment, to confirm the principle of such physical fields acting on micro-fluid. Second, we will design and manufacture micro-structure of sections and integrate those parts into an active micro-fluidic system via an electronic control circuit. Third, we will build a test platform, which is used to test the performance of various sections of the system. Finally, taking advantage of chemiluminescence reaction, we will test and evaluate the mixing effect of micro liquid-liquid two phase flow driven by the surface acoustic wave. The research of this project is a new field of mechanical manufacturing subject, and it involves in many cross-discipline subjects, such as driving micro-fluid by Surface Acoustic Wave, cooling and heating micro-flow based on heat transfering through graphene paper, liquid-liquid two phase micro-flow, designing and manufacturing microstructure and so on. To complete this project well, we will refer the new research conclusion of microelectronics subject. In the research period， the top-down-top schedule will be adopted according to the theory analyses and simulation conclusion. The micro-fabrication arts will be considered during the system design. The study achievement can be applied in health quarantine, expert testimony, environmental contamination monitoring, drug monitoring, micro chemical system and so on.

项目拟研究一种用于食品安全检测的新型流动注射式微流控系统，集成声表面波驱动和温度控制功能，提高微流体混合和化学反应的速度与效能。以黄曲霉素B1发光检测为目标，为我国的食品安全检测提供方便快捷的技术手段。主要研究内容包括揭示微环境下声场、电场和热场之间的耦合机理并建立数学模型；阐明声场、电场和热场对微流体混合的作用机理；在分子水平揭示耦合场对黄曲霉素免疫反应的作用机理；设计和制造各个功能模块的微结构；搭建相应的实验测试平台，测试微系统各个模块的功能，通过发光反应来测试和评价微流体混合和化学反应的效果等。研究项目涉及到声表面波驱动、介电泳驱动、微流控芯片温度控制、液液两相流、微结构设计与制造工艺等多个学科交叉领域，也是机械制造学科新的研究方向。项目的研究拟采取总体设计与分模块研究相结合的方式，充分借鉴微电子学科等已有的研究结论。研究成果可推广应用到卫生检疫、环境污染监测、毒品监控。

食品的快速、准确检测对于保证人民食品安全，提高人们的幸福指数有着意义。黄曲霉素的检测是食品安全检测的重要组成部分。本项目以黄曲霉素B1发光检测为目标，开发一种基于声表面波微流控技术的快速检测方法。主要研究内容包括揭示微环境下声场、电场和热场之间的耦合机理并建立数学模型；阐明声场、电场和热场对微流体混合的作用机理；在分子水平揭示耦合场对黄曲霉素免疫反应的作用机理；设计和制造各个功能模块的微结构；搭建相应的实验测试平台，测试微系统各个模块的功能，通过化学发光反应来测试和评价微流体混合和化学发光反应的效果等。研究结果表明，由于压电基底上存在压电效应和逆压电效应，声表面波传播过程中会伴随着产生交变的电场，声表面波微流控系统中的热效应和颗粒运动是声场和电场共同作用的结果，我们通过理论分析和实验验证研究了声表面波作用下热效应的产生机理；进一步地通过观察微流体中纳米颗粒的运动研究了声波传播过程中引起的声场、电场与热场对声流的影响规律，实验过程中通过控制变量法分别研究了三个物理场对声流的影响规律；声表面波驱动下产生的声流会影响分子间的相互作用，通过控制声表面波的参数可以控制物质的形状和晶型；在此基础上，通过设计和制作温度控制系统，成功地将声表面波微流控系统的温度控制在25℃左右，并通过理论仿真和实验验证对声表面波微流控器件进行优化，选择了角度为30°、距离为5mm的微流控器件；最终，通过黄曲霉素B1的发光检测实验验证了前期的研究。本研究成果为我国的食品安全检测提供方便快捷的技术手段，可推广应用到卫生检疫、环境污染监测、毒品监控等领域。