论文实时PCR聚合物芯片的总体结构和控制电路设计

1、PCR论文：实时PCR聚合物芯片的总体结构和控制电路设计【中文摘要】聚合酶链式反应(PCR)是一种体外模拟自然DNA复制过程的核酸扩增技术。它属于无细胞核酸扩增范畴,通过引物延伸核酸的某个特定区域而进行重复双向DNA合成,它具有灵敏度和特异性高,操作简便、快速的特点,并且反应体系有多种应用方式,能够适用于不同的核酸样品。聚合酶链式反应自从诞生之日起,就在基因工程和分子生物学方面展现了巨大的潜力,成为生物学实验室不可缺少的手段。本课题在前人研究的基础上设计了实时PCR聚合物芯片。首先介绍了PCR技术的变性、退火和延伸三个主要反应过程以及生化反应步骤,然后在生化反应步骤的基础上对PCR聚合物芯片进

2、行了总体结构设计。选择了结构简单易与集成的驱动单元电磁微泵,改进了人字形混合器结构,采用了铂电阻温度传感器和制冷装置,利用荧光对最终的扩增结果进行检测。本文的重点是设计适用于PCR反应的高密封性微阀。目前PCR系统中的微阀大都是微流控系统的通用阀,一般情况下不能满足PCR反应密封性高、温度承受性好和结构简单易于集成的要求。为了满足PCR聚合物芯片对微阀的要求,本文设计了一种适用于PCR反应的高密封性微阀。该阀的主体结构是一个长方体阀头连接着两个圆柱形阀杆共同组成的阀芯结构,其中阀头尺寸大于阀芯能够对流体进行二次密封,另外在盖片上还具有与阀杆结构尺寸相对应的通孔。阀芯在电机的驱动下能够与盖片上的

3、通孔配合。该阀的结构简单,仅靠一个伺服电机就能够实现阀的打开和关闭。利用ANSYS 11.0对所设计的电机伺服式微阀进行了热-结构分析,最终得出结论,此电机伺服阀的密封性与柱塞式微阀相当,适用于PCR反应。论文还在以上设计的基础上设计了聚合物芯片的控制系统,它包括硬件设计和软件设计。其中硬件设计部分选用AT89C51作为主控芯片,设计了泵和电机驱动所需的PWM信号。软件设计介绍了整个PCR控制的时序,利用VC+6.0提供的Active X控件Microsoft Communication Control编写设计了上位机界面。最后论文利用Protues软件对设计的控制系统进行了仿真,仿真结果表明

4、所设计的控制系统能够完成对泵和阀的控制。温度控制部分最大误差拟合后的测量值与温度计的实测值的偏差0.05。【英文摘要】Polymerase chain reaction (PCR) has been a popular technique for DNA amplification which is a kind of DNA amplification technique outside the body. Amplification of nucleic acids is essential for many biological applications. A single DNA mo

5、lecule can be copied a billion times to allow easy detection. PCR microchips are potentially low cost, disposable and possible for handheld instruments to be manufactured. Owing to the progressive development of PCR over the last two decades, it has become a central technique for nucleic acid analys

6、is and is the most widely used method for DNA amplification in Laboratory.Combining the research fruit of the domestic and overseas, this paper studies the realization of the PCR on a microchip.First we introduced the process denaturation, annealing and extension of PCR and biochemical reaction step

7、s, and then developed a simple polymeric PCR microchip. In the PCR microchip, we integrated a micro ectromagnetic pump, improved the staggered herringbone mixer which was designed by Stroock. At last, we adopted microheater and fluorescence detection micro apparatus department.The main research topi

8、c of the paper is designing a suitable microvalve for PCR. Currently the microvalves used in PCR were common valves which were not meeting the requirements of PCR, such as high sealing. So we designed a microvalve which specifical for PCR. The microvalve, with the stub and stem components, was posit

9、ioned directly above the plate with drilled holes identical to stem. The motor provided the force necessary to actuate the valve. It incorporated in the integrated chip conceptually utilizes an airtight plugging mechanism to prevent fluid loss from open-to-ambient drilled access holes on the upper s

10、ubstrate of the chip. In addition to the snug fit, application of thrust above the stub of the microvalve will also ensure a tight seal inside the access holes. At last, we designed thermal-structural analysis for the microvalve using ANSYS 11.0 and concluded that the microvalve was more suitable th

11、an passive plug microvalve. The hardware control circuit and software control design are introduced according to the characteristics of the PCR microchip. In the hardware design, we used AT89C51 as the center controlling part. A kind of PWM power used in micropump and valve were designed. In the sof

12、tware design, we introduced the timing of the PCR control systerm and using Microsoft Communication Control designed the PC interface, which was provided by VC+6.0. Finally, we simulated the designing control system by Protues. Experiment results show that the control system satisfied the design req

13、uest of micropump and valve, and the largest measurement error of temperature control0.05.【关键词】PCR 驱动单元 微阀 密封 控制【英文关键词】PCR micropump microvalve sealing control【目录】实时PCR聚合物芯片的总体结构和控制电路设计 摘要 11-13 Abstract 13-14 第1章 绪论 15-21 1.1 课题的研究背景与意义 15-17 1.2 国内外的研究现状 17-18 1.2.1 PCR系统的研究现状 17-18 1.2.2 微阀的研究现状

14、18 1.3 主要研究内容 18-21 第2章 PCR聚合物芯片总体结构设计 21-31 2.1 聚合酶链式反应 21-22 2.1.1 PCR技术的基本原理 21-22 2.1.2 PCR反应生化分析步骤 22 2.2 PCR芯片驱动单元 22-25 2.3 PCR芯片混合单元 25-27 2.4 PCR芯片温度控制单元 27-28 2.5 PCR芯片检测单元 28-30 2.6 本章小节 30-31 第3章 适用于PCR反应的高密封性微阀设计 31-55 3.1 适用于PCR反应的微阀研究 31-34 3.1.1 PCR微阀的性能特点 31-32 3.1.2 高密封性微阀的相关报道 32-

15、34 3.2 微阀材料选择及其加工方法 34-36 3.2.1 材料的选取 34-35 3.2.2 加工方法 35-36 3.3 微阀结构设计 36-45 3.3.1 PCR反应腔结构设计 36-37 3.3.2 微流体通道横截面设计 37-38 3.3.3 混合样式设计 38-39 3.3.4 试剂进样口设计 39-40 3.3.5 柱塞式阀芯设计 40-42 3.3.6 盖片设计 42 3.3.7 盖片与微流体通道的键合 42-43 3.3.8 微电机的选择 43-44 3.3.9 电机与微阀的传动机构设计 44-45 3.4 微阀的总体结构及工作原理 45-47 3.5 微阀性能仿真 4

16、7-52 3.5.1 新型微阀性能仿真 47-51 3.5.2 柱塞式微阀性能仿真 51 3.5.3 微阀性能比较 51-52 3.6 本章小节 52-55 第4章 PCR聚合物芯片控制系统设计 55-69 4.1 硬件控制系统总体方案设计 55-56 4.2 功能器件的选择 56-57 4.2.1 微处理器的选择 56 4.2.2 传感器的选择 56-57 4.3 MCU外围电路设计 57-58 4.4 转换电路设计 58-60 4.4.1 A/D转换电路 58-59 4.4.2 D/A转换电路 59-60 4.5 电机驱动电路设计 60-62 4.5.1 逻辑控制电路 60-61 4.5.2 功率驱动电路 61-62 4.6 系统软件设计 62-68