Electromechanically driven variable-focus lens based on transparent dielectric elastomer

Abstract

Dielectric elastomers with low elastic stiffness and high dielectric constant are smart materials that produce large strains (up to 300%) and belong to the group of electroactive polymers. Dielectric elastomer actuators are made from films of dielectric elastomers coated on both sides with compliant electrode material. Poly(3,4-ethylenedioxythiophene) (PEDOT), which is known as a transparent conducting polymer, has been widely used as an interfacial layer or polymer electrode in polymer electronic devices. In this study, we propose the transparent dielectric elastomer as a material of actuator driving variable-focus lens system using PEDOT as a transparent electrode. The variable-focus lens module has light transmittance up to 70% and maximum displacement up to 450. When voltage is applied to the fabricated lens module, optical focal length is changed. We anticipate our research to be a starting point for new model of variable-focus lens system. This system could find applications in portable devices, such as digital cameras, camcorder, and cell phones.

Dielectric Elastomers as EAPs: Applications

“…Other types of demonstrated DEA-based tunable lenses include systems where a liquid is pumped back and forth from the lens region by means of hydrostatically coupled DEA membranes (Niklaus et al 2010;Wei et al 2014;Liang et al 2014) or where transparent compact structures have been obtained by coating with conductive-polymer-based transparent electrodes either liquid-based lenses (Shian et al 2013) or single buckling membranes (Son et al 2012). …”

Investigation on the viscoelastic behaviors of a circular dielectric elastomer membrane undergoing large deformation

“…1 In addition to the capability of large deformation, DEs have other intrinsic attributes, such as light weight, high efficiency, low cost, noise free etc., which make them attractive for applications as transducers in artificial muscles, actuators and sensors, energy harvesters, soft robotics, adaptive optics etc. [2][3][4][5][6][7][8][9][10] To deform the DE transducers distinctly, usually, the required electric field is huge and the DE transducers commonly consist of thin, flat or cylindrical membranes. 1,10,11 As a consequence, the DE transducers may suffer from several modes of failure, such as electric break down, electromechanical instability, loss of tension, etc., which would degrade their performance.…”

High-speed, compact, adaptive lenses using in-line transparent dielectric elastomer actuator membranes

“…The primary consequence of placing the actuator outside the optical path is that a significant fraction of the lens' lateral area is occupied by the actuating mechanism, reducing the usable optical area. The use of transparent DEAs for lenses was recently demonstrated, but as the lens consists of a buckling solid elastomer membrane, it only operates as a diverging optic [11].…”