title: Mechanical modeling of fluid-driven polymer lenses.
abstract: A finite-element model (FEM) is employed to study the pressure response of deformable elastic membranes used as tunable optical elements. The model is capable of determining in situ both the modulus and the prestrain from a measurement of peak deflection versus pressure. Given accurate values for modulus and prestrain, it is shown that the two parameters of a standard optical shape function (radius of curvature and conic constant) can be accurately predicted. The effects of prestrain in polydimethylsiloxane (PDMS) membranes are investigated in detail. It was found that prestrain reduces the sensitivity of the membrane shape to the details of the edge clamping. It also reduces the variation of the conic constant with changes in curvature. Thus the ability to control the prestrain as well as thickness and modulus is important to developing robust optical designs based on fluid-driven polymer lenses.
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, Florida 33124, USA.
authors.forename: Qingda
authors.initials: Q
authors.lastname: Yang
authors.forename: Paul
authors.initials: P
authors.lastname: Kobrin
authors.forename: Charles
authors.initials: C
authors.lastname: Seabury
authors.forename: Sridhar
authors.initials: S
authors.lastname: Narayanaswamy
authors.forename: William
authors.initials: W
authors.lastname: Christian