A Compliance-Based Microflow Stabilizer

• Published in: Journal of microelectromechanical systems Vol. 18; no. 3; pp. 539 - 546
• Main Authors: Yang, Bozhi, Lin, Qiao
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.06.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied fluid mechanics; Applied sciences; Biomembranes; Circuits; Compliant membrane; Computational fluid dynamics; Devices; Exact sciences and technology; flow rectification; flow stabilization; Fluctuation; Fluctuations; Fluid dynamics; Fluid flow; Fluid flow control; fluid-structure interaction; Fluidics; Fluids; Fundamental areas of phenomenology (including applications); Instruments, apparatus, components and techniques common to several branches of physics and astronomy; lumped-parameter model; Mathematical models; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Membranes; Microchannel; Microfluidics; Micromechanical devices and systems; Micropumps; Physics; Precision engineering, watch making; Pumps; Studies; Vibrations; Open section beam; Membranes; Flow rate; Pipe flow; Fluid flow; Steady flow; Experimental study; Compliant membrane; Vibrations; fluid-structure interaction; flow rectification; Pulsatile flow; Squeeze film; flow stabilization; Lumped parameter system; Modelling; Thin walled beam; lumped-parameter model; Microelectromechanical device; Microfluidics; Fluidics
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2009.2021826

This paper presents a microfluidic device that can passively reduce fluctuations in an upstream fluid flow and generate a largely steady flow in a microfluidic system. The device features a series of compliant membranes that form deformable walls of a microchannel. For an incoming pulsatile flow, passive vibrations of the membranes allow the fluid to be accumulated for an overflow and discharged for an underflow, resulting in drastically reduced fluctuations in flow rate and pressure. A lumped-parameter model is developed to simulate the device characteristics, in which the coupling of membrane vibrations and fluid flow in individual channel sections associated with a single membrane is first represented by squeeze-film theory and inertia-free structural dynamics. The entire device is next represented as a system by connecting individual channel sections in series. The model is numerically solved, and the results agree with experiments. The theoretical and experimental results both show that a five-membrane device can stabilize a pulsating flow by a factor of about 20. These results also reveal that smaller average flow rate, smaller fluctuation, and higher fluctuation frequency lead to more effective flow stabilization. With these characteristics, the flow stabilizer can be used to obtain steady flow in microfluidic systems.