FINITE ELEMENT ANALYSIS OF DIELECTRIC ELASTOMER-BASED VARIABLE FOCAL LENGTH REFLECTOR

Abstract

Dielectric Elastomers (DEs) belong to the class of soft actuators which are employed to perform biomimetic actuation. These actuators have promising future applications in many fields, including adaptive optics. The primary objective of the author is to analyze DE based variable focal length mirror using finite element method. This type of mirror find many potential applications in adaptive optics. In this thesis, an electromechanically coupled finite element model is developed to do static analysis of any configuration of dielectric elastomer actuators. The material model of the elastomer is assumed to be neo-Hookean hyperelastic material model. This finite element model is validated by using lump parameter model for a homogeneous configuration. Using this model, pull-in instability parameters are obtained for homogeneous freely expandable circular DEA. Using this model, DE based disk shaped buckling actuators are analyzed, which can be used as variable focal length mirrors as their special application. This analysis is done for circular disk shaped DEAs provided with appropriate boundary conditions. By varying different parameters of boundary conditions, responses of these reflectors are obtained. It is found that the profile of the actuated mirror is parabolic in its most of the working voltage range. By using this profile, the variation of focal length is also derived. The final conclusion includes the effects of different parameters on deformation of the actuators