Fluid-Structure Interaction in Deformable Microchannels

TL;DR

This study investigates fluid-structure interactions in deformable microchannels using experiments and computational models, revealing the conditions under which simplified models accurately predict membrane deformation.

Contribution

It compares 2D and 3D models with experiments to identify when simplified assumptions are valid for deformable microchannel analysis.

Findings

2D model approximates 3D model well under certain conditions

Experimental data agrees with computational predictions

Critical membrane width is about twice its length

Abstract

A microfluidic device is constructed from PDMS with a single channel having a short section that is a thin flexible membrane, in order to investigate the complex fluid-structure interaction that arises between a flowing fluid and a deformable wall. Experimental measurements of membrane deformation and pressure drop are compared with predictions of two-dimensional and three-dimensional computational models which numerically solve the equations governing the elasticity of the membrane coupled with the equations of motion for the fluid. It is shown that the two-dimensional model, which assumes a finite thickness elastic beam that is infinitely wide, approximates reasonably well the three-dimensional model, and is in excellent agreement with experimental observations of the profile of the membrane, when the width of the membrane is beyond a critical thickness, determined to be roughly twice the length of the membrane.