MEMS-Based Thermal and Mass-Transport Control for Microfluidic BiochemicalReagent Mixing and 2-D Gas Chromatography.

MEMS;Microfluidics;PCR;Gas Chromatography;Thermal Modulator;Mechanical Engineering;Engineering;Mechanical Engineering

Kim, Sung JinZellers, Edward T. ;

University of Michigan

关键词: MEMS;    Microfluidics;    PCR;    Gas Chromatography;    Thermal Modulator;    Mechanical Engineering;    Engineering;    Mechanical Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/77914/yahokim_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This research demonstrates the use of microelectromechanical systems (MEMS) technology to control microscale heat and mass transfer for lab-on-a-chip biochemical assays and the analysis of complex vapor mixtures.Toward this goal, we have developed two microdevices, namely (1) a micromixer and (2) a microthermal modulator.The micromixer uses natural convection to greatly simplify the micromixing process in a microfluidic network, whereas the microthermal modulator utilizes forced convection to manipulate vapor samples in a fast, low-power consuming manner within a comprehensive 2-D gas chromatography system. In a microfluidic network, micromixing is a crucial step for biochemical analysis. A critical challenge is that the microfluidic systems need numerous chambers and channels not only for mixing but also for biochemical reactions and detections.Thus, a simple and compatible design of the micromixer element for the system is essential.Here, we demonstrate a simple, yet effective, scheme that enables micromixing and biochemical reaction in a single chamber without using any mechanical components.We accomplish this process by using natural convection in conjunction with two alternating heaters for micromixing.As a model application, we demonstrate PCR and its reagent mixing in a single microfluidic chamber. Our results will significantly simplify the micromixing and subsequent biochemical reactions.In comprehensive two-dimensional gas chromatography (GCxGC), a modulator is placed at the juncture between two separation columns to focus and re-inject eluting mixture components, thereby enhancing the resolution and the sensitivity of the analysis.Here, we present the design, fabrication, thermal operation, and initial testing of a two-stage microscale thermal modulator (µTM).The µTM contains two sequential serpentine Pyrex-on-Si microchannels (stages) that cryogenically trap analytes eluting from the first-dimension column and thermally inject them into the second-dimension column in a rapid, programmable manner with low thermal crosstalk between the two stages.A lumped heat transfer model is used to analyze the device design with respect to the rates of heating and cooling, power dissipation, and inter-stage thermal.Preliminary tests using a conventional capillary column interfaced to the µTM demonstrate the modulation of a mixture of alkanes.