Optimization of elstomeric micro-fluidic valve dimensions using non-linear finite element methods

H Khawaja, I Raouf, K Parvez, A Scherer


We use a nonlinear finite element (FE) method model to compare,optimize and determine the limits for useful geometries of microfluidicvalves in elastomer polydimethylsiloxane (PDMS). Simulations havebeen performed with the aim of finding the optimal shape, size andlocation of pressurization that minimizes the pressure required to operatethe valve. One important constraint governing the design parameters isthat the stresses should be within elastic limits, so that the componentremains safe from any type of structural failure. To obtain reliable results,non-linear stress analysis was performed using the Mooney-Rivlin 9parameter approximation which is based on the Hyper Elastic MaterialModel. A 20 noded brick element was used for the development of FEmodel. Mesh sensitivity analysis was also performed to assess the qualityof the results. The simulations were performed with commerciallyavailable FE modeling software, developed by ANSYS Inc. to determinethe effect of varying different geometric parameters on the performanceof micro-fluidic valves.The aim of this work is to determine the geometry of the channel crosssectionthat would result in the largest deflection for the least appliedpressure, i.e. to minimize the pressure needed to operate the valve.

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Kangsun Lee et al, Fabrication of round channels using the surface tension of PDMS and its application to a 3D serpentine mixer, Journal of Micromechanics and Microengineering, 2007, 17, 1533-1541.

Kurt Miller, Testing Elastomers for Hyperelastic Material Models in Finite Element Analysis, Axel Products®Inc., June 2004, V3.

Marc A. Unger et al, Monolithic Microfabricated Valves and Pumps by Multilayer Soft Lithography, Science, 2000, 288 (113), DOI: 10.1126/science.288.5463.113

R. C. Huang and L. Anand, Non-linear mechanical behavior of the elastomer polydimethylsiloxane (PDMS) used in the manufacture of microfluidic devices, to be published

R. Quake et al, Experimentally validated quantitative linear model for the device physics of elastomeric microfluidic valves, Journal of Applied Physics, 2007, 10 (064505), DOI: 10.1063/1.2511688

J C Lotters et al, The mechanical properties of the rubber elastic polymer polydimethylsiloxane for sensor applications, Journal of Micromechanics and Microengineering, 1997, 7, 145-147.

Mark Lee Adams, Integration of Optoelectronics and Microfluidics for biological and chemical sensing, PhD, California Institute of Technology, 2003.

Multiphysics Software, ANSYS® Inc. Version 11.0.

Theory Reference, 1Structures, 2Hyperelastic Material Models, 3Non-Linear Analysis, ANSYS® Inc. Version 11.0.

Documentation, 1Structural Analysis Guide, and 2Verification Manuals, ANSYS® Inc. Release 11.0

Mario M et al, Hyperelastic constitutive modeling under finite strain, International Journal of Solids and Structures, 2004, 41, 5327-5350.

E. Cosola et al, A general framework for identification of hyper-elastic membranes with moiré techniques and multi-point simulated annealing, International Journal of Solids and Structures, 2008, 45, 6074-6099.

Ordieres-Meré a et al, Finite element analysis of the hyper-elastic contact problem in automotive door sealing, Journal of Non-Crystalline Solids, 2008, 354, 5331-5333.

Zhongbing Huang et al, Equilibrium of drops on inclined fibers, Journal of Colloid and Interface Science2008, 330 (2009), 399-403.

DOI: http://dx.doi.org/10.1260/175095409788837847

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