Equivalent circuit modeling and analysis of microflow stabilization through compliant microchannels.

摘要

Investigated in this thesis are the modeling and analysis of the stabilization of pulsatile flowrates through a compliant microchannel. Flowrate stabilization leads to improved performance in microfluidic systems that use mechanically driven pressure sources, which inherently develop pulsatile flowrates.;The hypothesis of this investigation is that the dynamics of a compliant walled microchannel can be modeled by a quasi-steady state representation from viscous flow theory, thereby making the channel tunable for low frequency attenuation of pulsatile flowrates. The walls of a compliant microchannel store and discharge a volume of fluid in response to a pulsatile inlet pressure. This results in the reduction of a pulsatile inlet flowrate to a steady state outlet flowrate. This thesis presents an equivalent circuit model representation of a microchannel based on an analogue between hydraulic and electrical domains. Flowrate and pressure data from experimental testing of microchannels, with deionized water as the working fluid, are recorded and analyzed. The accuracy between model predictions and outlet flowrate values during pulsatile pressure testing is reviewed. Experimental results confirm analytical predictions that a configuration of three microchannels joined in series successfully stabilizes a pulsatile flowrate with a hydraulic cutoff frequency of approximately 0.5 Hz. The extent to which the hypothesis is verified by the experimental results and the limitations of this stabilization method are discussed.