Adaptive Lenses Based on Soft Electroactive Materials

Abstract

Soft electroactive materials including dielectric elastomer actuators (DEAs) and polyvinyl chloride (PVC) gels have recently been extensively investigated. These smart materials can effectively respond to an electric field, resulting in shape deformation. In addition to artificial muscles, actuators, sensors, and micro-electromechanical systems, they can be used to prepare various adaptive lenses with unique features such as a simple fabrication, compact structure, good flexibility, and light weight. In contrast to DEAs, PVC gels can provide exciting opportunities for emerging applications in imaging, sensing, optical communication, biomedical engineering, and displays. In this review paper, the underlying physical mechanisms of these two electroactive materials are explained first, and then some recent progress in their application in macro-sized lenses and microlens arrays is presented. Finally, future perspectives of the PVC gels are discussed.

P‐81: Electrically Tunable GRIN Liquid‐Crystal Lenticular Lens Array with Short Focal Length

“…Liquid crystal is an effective medium because its optical anisotropy and dielectric anisotropy can be varied by electric field [1]. Controlling the alignment of the LC molecules by an electric field, an LC lens with gradient refractive index (GRIN) distribution can be achieved, which is most widely utilized in the fields of image processing, beam steering, wavefront correction, and switchable 2D/3D displays [2].…”

Engineering Aspheric Liquid Crystal Lenses by Using the Transmission Electrode Technique

“…These lenses show fast switching in combination with broad optical power range. The shape-changing technique embraces several structures, for example, based on elastic membranes [3][4][5][6], ferrofluidics [7][8][9], soft electroactive actuators [10], and the electrowetting and dielectrophoretic effect [11,12]. For this reason, the characteristics vary widely depending upon the nature of the surface or the physical effect.…”

Short focal length tunable liquid crystal lenticular lens array based on fringe field effect

“…[9][10][11][12] In the LC devices, LC molecules are an effective medium because its optical anisotropy and dielectric anisotropy can be varied by an electric field. 13 Because LC director's orientation is aligned along the electric field direction, light passing through the LC layer experiences a different refractive index by controlling the molecular orientation of the LC layer with an electric field; thus, a gradient refractive index (GRIN) profile can be generated, 14 which leads to a focal length tunable LC lens. This is a basic operation principle, which can be utilized to realize LC lenses with GRIN profile through quite a number of approaches.…”

“…A liquid crystal (LC) microlens array is an essential electrooptical device for many applications, including image processing, 1–5 beam steering, 6,7 wavefront correction, 8 and 2D/3D switchable displays 9–12 . In the LC devices, LC molecules are an effective medium because its optical anisotropy and dielectric anisotropy can be varied by an electric field 13 . Because LC director's orientation is aligned along the electric field direction, light passing through the LC layer experiences a different refractive index by controlling the molecular orientation of the LC layer with an electric field; thus, a gradient refractive index (GRIN) profile can be generated, 14 which leads to a focal length tunable LC lens.…”