PDMS Material Models for Anti-fouling Surfaces Using Finite Element Method

Abstract

Ecofriendly anti-fouling surfaces are usually produced by lithographic techniques which will fabricate micropillar-like surfaces made of low surface energy materials such as Polydimethylsiloxane (PDMS). The purposes of this research were to investigate the most suitable Polydimethylsiloxane (PDMS) material model available in ANSYS APDL program to simulate structural behaviors of micropillars subjected to shear loading and to develop micropillar with improved lateral strength. In this research, PDMS material models were derived from experimental data from uniaxial tensile test. The accuracies of the PDMS material models, which were the Neo-Hookean, Mooney-Rivlin 3 and 5 parameters, Ogden (1, 2, 3 terms), Yeoh (1^st, 2^nd, 3^rd order) and Arruda-Boyce material models, were evaluated and compared to experimental data from uniaxial tensile test and punch-shear test. Moreover, micropillars made of a pure PDMS and a Polyurethane Acrylate (PUA) core coated with PDMS were studied to compare their lateral strength under shear loading. We found that the most accurate material model to simulate both the uniaxial tension and shear loading was the Yeoh 3rd order material model; however, these accuracies would valid for small strain range. The lateral strength of a micropillar made of PUA core coated with PDMS was 8.67-time of the one made of pure PDMS. The thickness of the coated material was not a significant effect on lateral strength of the micropillar.