Characterization of the mechanical properties of microscale elastomeric membranes

This paper reports on a novel method to characterize the mechanical properties, such as the elastic modulus, of circular microfabricated elastomeric membranes by measuring their load-displacement curve (compliance). An ultra-precision instrument was developed to simultaneously measure both the applied forces and the resultant displacements of the membrane under a central load. During all the deformation experiments, a high-resolution optical microscope system was used for viewing the side-view of the deformed membrane and thereby the complete membrane deflection profile was obtained. In the current experiment, measurements were performed on a set of thin, circular silicon rubber membranes with a thickness of 180 mu m. A theoretical linear elastic solution was applied to quantitatively correlate the elasticity to the measured membrane compliance under such a central point load. Viscoelastic response of the membranes used was not manifested; therefore, it had no effect on the determination of Young's modulus of the membranes in the current work. The good agreement between the experimental results and the theoretical analyses facilitates the determination of Young's modulus of the membrane.