On-Chip, Switchable Osmotic Actuation for Programmable, Passive Microfluidic Pumping

• Main Authors: Peng, Po-Jui, 彭柏睿
• Other Authors: Su, Yu-Chuan
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/95918515304134320978

碩士 === 國立清華大學 === 工程與系統科學系 === 100 === In the past few years, micro-electro-mechanical-systems (MEMS) technology and micromachining techniques have enabled the miniaturization of biomedical and chemical analysis devices and systems. Furthermore, technologies for realization of microfluidic systems have been demonstrated since the advent of micro-total-analysis-system (u-Tas).The micropump is the most important device for purpose of the automation in the microfluid system. In this article, we present a novel passive fluid-driven control method, without external power and can achieve the purpose of the sample fluid drive and timing control. In this way, it can be developed a portable microfluidic-driven and automatic control chip, The user only needs to drop a few water to start this system. The system is generally divided into three PDMS layers, the top and bottom are control channel and fluid channel, respectively, and the middle of two layers are added a layer of PDMS membrane as a medium for the promotion of the sample fluid, and we can drive and control sample fluid by deforming the PDMS membrane. Basically, we use osmosis as the power source of the driving and controlling the fluid, hence, it have the advantages of constant flow rate and high driving pressure. The flow of control fluid will squeeze the membrane, replace the piston and the traditional mechanisms of fluid driving to drive the lower sample fluid. We also design a series of pressure sensitive switch, time delay channel , check valve integrated and negative pressure source to successfully achieve the passive microfluidic drive and control chip with automatic filling of the sample, as well as stagnation and flow rate automatically switching, which according to our geometric space configuration with semi-permeable membrane permeable area to effectively control the parameters of the sample output flow rate and delay time. Followed by our experimental setup, we can drive the sample output with 0.095mm3/s in about 30 second and stop it in about 220 second, and finally drive it with the same flow rate in about 20 second once again. This method can be effectively expanded to control the role of multiple switches and valves to create a complex and diverse functions, portable detection system is expected to be applied automatically to complete a series of quantitative and timing detection action, simplify raw medical and chemical detection processes and reduce costs to achieve the goal of micro-total-analysis-system.