Deformation properties between fluid and periodic circular obstacles in polydimethylsiloxane microchannels: Experimental and numerical investigations under various conditions

Abstract

Understanding the mechanical properties of optically transparent polydimethylsiloxane (PDMS) microchannels was essential to the design of polymer-based microdevices. In this experiment, PDMS microchannels were filled with a 100 lM solution of rhodamine 6G dye at very low Reynolds numbers ($10 À3 ). The deformation of PDMS microchannels created by pressure-driven flow was investigated by fluorescence microscopy and quantified the deformation by the linear relationship between dye layer thickness and intensity. A line scan across the channel determined the microchannel deformation at several channel positions. Scaling analysis widely used to justify PDMS bulging approximation was allowed when the applied flow rate was as high as 2.0 ll/min. The three physical parameters (i.e., flow rate, PDMS wall thickness, and mixing ratio) and the design parameter (i.e., channel aspect ratio ¼ channel height/channel width) were considered as critical parameters and provided the different features of pressure distributions within polymer-based microchannel devices. The investigations of the four parameters performed on flexible materials were carried out by comparison of experiment and finite element method (FEM) results. The measured Young's modulus from PDMS tensile test specimens at various circumstances provided reliable results for the finite element method. A thin channel wall, less cross-linker, high flow rate, and low aspect ratio microchannel were inclined to have a significant PDMS bulging. Among them, various mixing ratios related to material property and aspect ratios were one of the significant factors to determine PDMS bulging properties. The measured deformations were larger than the numerical simulation but were within corresponding values predicted by the finite element method in most cases. V C 2013 AIP Publishing LLC. [http://dx

Uncovering the Contribution of Microchannel Deformation to Impedance-Based Flow Rate Measurements

“…In the case where w ≫ h , as is the case of the microchannels used in Figures –, a larger deformation of the channel height was observed while the lateral deformation was negligible. This phenomenon was also described in other studies. , In general, flow resistance is larger in smaller channels. If we keep the same channel height while changing the channel width, the same volumetric flow rate is maintained.…”

“…This phenomenon was also described in other studies. 18,22 In general, flow resistance is larger in smaller channels. If we keep the same channel height while changing the channel width, the same volumetric flow rate is maintained.…”

Pressure-driven deformation with soft polydimethylsiloxane (PDMS) by a regular syringe pump: challenge to the classical fluid dynamics by comparison of experimental and theoretical results

“…Shallow microuidic channels (15 mm) were fabricated by wet etching, while three deeper microuidic channels (50 mm, 100 mm and 200 mm) were fabricated by reactive ion etching (RIE) techniques for making high-aspect-ratio structures with high etching rates, straight sidewalls and complex geometries. 27 Detail information about design and chip fabrications described by Kang et al 28 The microuidic channels produced by these procedures contained fabricated microuidic channels with a measured width of 243 AE 5 mm and measured heights of 15 AE 1 mm, 50 AE 2 mm, 100 AE 5 mm and 200 AE 8 mm, respectively.…”

Property Investigation of Replaceable PDMS Membrane as an Actuator in Microfluidic Device

“…Schneider et al [41,44] demonstrated an adaptive fluidic PDMS-lens system with an integrated piezoelectric pumping actuator. Because PDMS membrane devices are widely used in the microfluidic field as actuator, the correlation between thickness, applied pressure, and deflection properties of PDMS membrane has been theoretically and experimentally investigated, such as PDMS channel expansion, deformation and bulging [46][47][48]. Mechanical properties of PDMS have also been investigated, including shear modulus, thickness-spin speed dependence and adhesion, and true stress-based true strain by mechanical tension testing [49][50][51].…”