Triple-layer spherical electrowetting liquid lens with large-aperture and high zoom ratio

Abstract

We propose a triple-layer spherical electrowetting liquid lens with large-aperture and high zoom ratio. The chamber of the proposed lens is spherical, which can enlarge the apparent contact angle range. The triple-layer liquid consists of a conductive liquid, an insulating liquid and a conductive liquid in turn, which forms two independent liquid-liquid (L-L) interfaces. We simulated and analyzed the geometric location of the L-L interfaces to ensure that the two liquid-liquid interfaces do not fuse under the requirement of compact design. The two L-L interfaces are symmetrically distributed on the upper and lower hemispheres of the spherical chamber and can be changed the surface shapes at the same time. The experimental results show that the zoom ratio of our proposed lens is 4.12. And the focal length can be changed from −35.2 mm to 51.1 mm under 0–80 V applied voltage, and has two focal segments according to different working electrodes. 8 mm clear aperture and 6 mm total liquid thickness mean that the triple-layer spherical electrowetting liquid lens can be pretty compact and has a great application prospect in imaging systems, such as microscopic imaging system, etc.