Electrowetting lens based on a conical aluminum cavity

Abstract

A tunable liquid lens based on the electrowetting-on-dielectric effect is demonstrated using a machined aluminum substrate. A metallic substrate eliminates the need for deposited electrodes inside the droplet cavity and simplifies the fabrication procedures required to produce an electrowetting optic. Sloped sidewalls at 45° produce a large optical tuning range, with back focal length tuning from [−134, −18.5 mm] and [+11.3, +134 mm]. An input-shaped overdriven actuation voltage yields a response time of 149 ms. The aluminum substrate is machined using standard processes that allow the device geometry to be customized. A complete lens package is sealed with fluoroelastomer O-rings, enabling applications beyond the laboratory environment.