Tunable lenses using transparent dielectric elastomer actuators

Samuel Shian,Roger M Diebold,David R Clarke

doi:10.1364/oe.21.008669

Abstract

Focus tunable, adaptive lenses provide several advantages over traditional lens assemblies in terms of compactness, cost, efficiency, and flexibility. To further improve the simplicity and compact nature of adaptive lenses, we present an elastomer-liquid lens system which makes use of an inline, transparent electroactive polymer actuator. The lens requires only a minimal number of components: a frame, a passive membrane, a dielectric elastomer actuator membrane, and a clear liquid. The focal length variation was recorded to be greater than 100% with this system, responding in less than one second. Through the analysis of membrane deformation within geometrical constraints, it is shown that by selecting appropriate lens dimensions, even larger focusing dynamic ranges can be achieved.

Highlights

Compact, adaptive focus lenses are attractive for imaging applications where space is at a premium, including endoscopes, cell phone cameras, and machine vision apparatus
The focal length variation was recorded to be greater than 100% with this system, responding in less than one second
To further improve the simplicity and compact nature of adaptive lenses, we present an elastomer-liquid lens system which makes use of an inline, transparent electroactive polymer actuator

Summary

Introduction

Adaptive focus lenses are attractive for imaging applications where space is at a premium, including endoscopes, cell phone cameras, and machine vision apparatus. A variety of actuation mechanisms are used to drive the deformation of these tunable lenses, including electric motors, rotating screws, piezoelectric elements, or dielectric elastomer actuators (DEAs). Each of these existing adaptive lens configurations locates the actuator outside the optical path. 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 [10] The purpose of this communication is to describe a self-contained tunable lens with an integrated electrical actuator in the optical path of the lens. An analysis of the membrane deformation and optical properties of the lens will be discussed

Lens design

Fabrication

Results

Conclusions