【作者】 宋宇；

【导师】 王蔚；

【作者基本信息】 哈尔滨工业大学 ， 微电子学与固体电子学， 2009， 硕士

【摘要】 微流控芯片技术是20世纪90年代初出现的一门新技术,以MEMS技术为依托,将微沟道、微储液池、微反应器等微结构集成到一块很小的芯片上,以可控流体贯穿系统,实现传统实验室的功能。对试样进行检测分析是微流控芯片最重要的功能之一,因此检测系统成为微流控芯片系统设计的关键。在众多检测方法中,紫外-可见吸收光度检测普适性最好,但其检测灵敏度相对较低,同时系统体积较大,不便于携带,几乎抹杀了微流控芯片微小化的优势。因此,有必要在研制便携式系统和提高检测灵敏度方面进行研究。论文对微流控芯片紫外检测过程进行了分析,提出了一种利用PMMA材料对280nm~320nm紫外光的半透性质阻挡杂散光、实现光学狭缝的设想,对其可行性进行了理论验证。研制了一种手掌大小的便携式微流控芯片紫外检测系统,可使用电池供电;系统采用高灵敏光敏二极管,精确的模拟电路设计,整合了单片机控制系统,实现了微弱信号检测、数据采集、串口通信、高压控制等功能的集成。单片机系统以定时中断程序为中心,响应及时,可靠性高。完成了上位机软件设计,软件界面友好,易于操作,有一定抗干扰能力。经测试,系统无光情况下噪声约在±4mV左右,无漂移现象。对几种不同浓度的氯离子进行了检测,峰高、峰宽和出峰时间重复性均较好。对0.5mmol/L的氯离子检测信号约60mV,基本达到系统检测限。实验证实,本系统可实现微流控芯片上试样的紫外吸收光度检测。更多还原

【Abstract】 Micro-fluidic chip technology, which roots in MEMS technology, was brought up in the beginning of 1990s. It integrates the micro-channels, micro-chambers, micro-reactors and other micro-structures on a single microchip, with the controllable fluid throughout the whole system to build a lab on a chip. Sample analysis and detection is the most important function of a micro-fluidic chip, thus the detection device is the most vital part of the system. Among a number of detection methods, UV absorbance detection method is universal for almost all kinds of application circumstance. But its sensitivity is lower than other methods. And its large bulk obliterates the profit of miniaturization of micro-fluidic chips. Hence, it’s necessary to study on a portable UV absorbance detection system with high sensibility.In this work, the UV detection process on a micro-fluidic chip was analyzed theoretically at first. A method for the system’s slit was presented and verified in theory with PMMA which is translucent to ultraviolet radiation whose wavelength is from 280nm to 320nm. The system including a high sensitive photodiode, a kind of precise analog circuit and a MCU system, achieves the function of low signal detection, data acquisition, communication, and voltage control. Based on the interrupt process, the MCU system has punctual response and high reliability. The position-machine software was designed with friendly interface, flexible operation and anti-interference ability.The test result showed±4mV system noise in a dark environment without any drift. The detection of different concentration of Cl- showed high signal reproducibility in the height, the wide and the arriving time of the signal peak. The limit of detection is about 0.5mmol/L for Cl- with 60mV signal. Experimental results indicate that this detection system is suitable for UV absorbance detection micro-fluidic chip.更多还原