A microfluidic transistor for analog micro-flows control -

Abstract

In this work, a microfluidic device for analog flow control is presented. The device consists of a microchannel with an elastic compliant wall where the fluid flow-rate is controlled by the combined effect of the pressure differential across the channel and the deflection of the elastic wall. A reduced-order model that captures the steady and lowfrequency unsteady behavior of the device is presented. The model is based on coupling the equations governing the membrane deflection and fluid flow while employing some assumptions to reduce their complexity. Numerical simulations ANSYS-Fluent are used for characterizing the device behavior in terms of dependence of the flow rate on the operating pressure differences; in a manner analogous to analogous to standard characterization of electronic transistors. In addition to the characteristic curves, the reduced order parameters (i.e. the fluidic transconductance, intrinsic output resistance, and gain) are generate dover wide ranges of operating pressures. Accuracy of the proposed reduced-order model is assessed by comparing with ANSYS fluid-structure interaction (FSI) simulation. Finally an applications of how the transistor can be used is presented in for two examples: (i) in a common source circuit configuration for small signal amplification, and (ii) as an analog flow controller for mixing of two pulsating flows.