【作者】 廖明城；

【导师】 于军；

【作者基本信息】 华中科技大学 ， 微电子学与固体电子学， 2011， 硕士

【摘要】 生物芯片是20世纪具有划时代意义的微量分析检测技术,广泛应用于疾病诊断和治疗、药物筛选、基因测序、中药物种鉴定、农作物优育优选等许多领域。作为生物芯片技术的一种,聚合酶链式反应技术自诞生以来不断发展成熟起来,应用前景越来越广泛。聚合酶链式反应(Polymerase Chain Reaction, PCR)是一种能够在数小时内使特定DNA片段扩增到数百万个拷贝的体外快速扩增DNA的方法,已广泛应用于生物科学、医学等领域。DNA的扩增过程可分为变性(93~94℃)、退火(54℃)、延伸(72℃)三个连续的、循环的温度操作过程。因此,温度是影响PCR扩增的一个关键因素。本文设计了基于MEMS技术的PCR芯片系统,在玻璃基片上设计了微反应腔式PCR芯片。芯片上集成了DNA微反应室、加热器及温度传感器,芯片尺寸大小为10mm*10mm*0.5mm,微反应室的尺寸大小为5mm*5mm*0.15mm。芯片底面通过光刻、溅射等工艺制作了微型加热器与温度传感器,以使PCR芯片测温、控温更简便。为使芯片温区温度分布更均匀,通过ANSYS软件对不同结构的加热器进行温度场仿真,得到最优的加热器结构。PCR芯片温度控制系统的设计,包括硬件和软件两部分。硬件的设计主要包括信号采信、信号调理、CPU系统和控制信号输出几部分。在信号采集部分为避免铂电阻温度传感器因电流流过而产生焦耳热,系统采用0.5mA恒流源电路。采集电路将系统的温度信号转化为电压信号后,经放大、滤波后,由SPCE061A的I/O口采集。采集到的电压信号经计算转化为的温度值后与设定的温度值进行比较,经PID算法计算及相应的比例换算获得相应占空比的PWM方波以控制固态继电器的通断,实现芯片PCR反应温度的自动控制。本文还从理论上证明了PCR芯片系统设计的合理性,并进行了简单的实验来验证系统设计的可行性。更多还原

【Abstract】 Biochip is a landmark trace analytical techniques developed at the end of last century, which are widely used in disease diagnosis and treatment, drug genome atlas, drug screening, gene sequencing, crop dabbling optimization, food hygiene supervision and many other areas. As a kind of biological chip, PCR chip technology develops ceaselessly, which is a kind of DNA vitro expansion method.The Polymerase Chain Reaction (PCR) which can make specific DNA segments swell to millions of copies in a matter of hours has been widely applied in biology science, medicine and so on. DNA amplification process can be divided into degeneration (93 ~ 94℃), annealing (54℃), extension (72℃) three consecutive and circulates temperature operation process. Therefore, the temperature is one of the key factors of PCR chip.The paper designed a micro reaction chamber PCR chip based on MEMS technology in glass. The chip contained a DNA micro-reactor room, a heater and a temperature sensor, which size is about 10mm *10mm* 0.5 mm. Using wet etching methods in glass to etch out a 5mm *5mm * 0.15 mm micro-reactor room. On the other side of the PCR chip there is heater and temperature sensor in order to make the PCR chip miniaturization and integration. To make temperature more uniform, we used ANSYS software to simulate different structures of the heater on temperature field to search for optimal heater structure.The paper designed a cyclic temperature control system, which included both hardware and software. The hardware design included signal acquisition part, signal disposal part and control signal output part. To avoid platinum generate heating because of large current, signal acquisition circuit adopted 0.5 mA constant-current source circuit. Acquisition circuit transformed temperature signal into voltage signal, which is acquitted by SPCE061A I/O ports after enlargement and filtering. The collected voltage signal is transformed into the value of temperature .After comparing with the setting value and PID calculation, it got a PWM square-wave to control the solid state relay, which realized automatic temperature control.更多还原