Wang Chih-Hao, Lee Gwo-Bin
Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan.
Biosens Bioelectron. 2005 Sep 15;21(3):419-25. doi: 10.1016/j.bios.2004.11.004. Epub 2004 Dec 15.
The present study reports a microfluidic system using the concept of membrane-movement to design and fabricate micro-pneumatic valves and pumps to form a bio-sensing diagnostic chip. The automatic bio-sampling system includes a micro-diagnostic chip fabricated by using MEMS (micro-electro-mechanical systems) technology and an automatic platform comprising of a control circuit, a compressed air source and several electromagnetic valve switches. The control circuit is used to regulate the electromagnetic valve switches, causing thin PDMS membranes to deflect pneumatically by the compressed air and generate valving and pumping effects. The micro-diagnostic chip allows for the quick detection of diseases. Compared to large-scale systems, the new microfluidic system uses smaller amounts of samples and reagents and performs fast diagnosis in an automated format. Instead of using traditional pneumatic micro-pumps, the current study adopts a new design called "spider-web" micro-pumps to increase the pumping rate, and more importantly, improve the uniformity of flow rates inside multiple micro-channels. Experimental data show that for disease diagnosis, the bio-sensing chips integrated with the micro-pneumatic valves and the peristaltic micro-pumps could successfully perform diagnosis tests. Small amounts of samples and reagents could be injected into the diagnosis chips using the micro-pumps and the micro-pneumatic valves could effectively control the movement of the samples and reagents. In order to demonstrate the functionality of the developed device, detection of hepatitis C virus (HCV) and syphilis has been performed using the bio-sampling chips. Experimental data show that fluorescence signals from the microfluidic system were comparable to the ones using conventional testing methods. The developed chip could be easily extended for multiple disease detection. The automatic bio-sensing chips could provide a useful tool for fast disease detection and be crucial for a micro-total-analysis system.
本研究报告了一种微流控系统，该系统利用膜运动的概念来设计和制造微气动阀和泵，以形成生物传感诊断芯片。自动生物采样系统包括一个采用微机电系统（MEMS）技术制造的微诊断芯片和一个由控制电路、压缩空气源和几个电磁阀开关组成的自动平台。控制电路用于调节电磁阀开关，使薄PDMS膜在压缩空气作用下气动偏转，产生阀门和泵送效应。微诊断芯片能够快速检测疾病。与大型系统相比，新的微流控系统使用的样品和试剂数量更少，并以自动化形式进行快速诊断。当前研究采用了一种名为“蜘蛛网”微泵的新设计来提高泵送速率，更重要的是，提高多个微通道内流速的均匀性，而不是使用传统的气动微泵。实验数据表明，对于疾病诊断，集成了微气动阀和蠕动微泵的生物传感芯片能够成功进行诊断测试。可以使用微泵将少量样品和试剂注入诊断芯片，微气动阀能够有效控制样品和试剂的移动。为了证明所开发设备的功能，已使用生物采样芯片对丙型肝炎病毒（HCV）和梅毒进行了检测。实验数据表明，微流控系统的荧光信号与使用传统检测方法获得的信号相当。所开发的芯片可以很容易地扩展用于多种疾病检测。自动生物传感芯片可为快速疾病检测提供有用工具，对微全分析系统至关重要。
