Variable-focus liquid lens for miniature cameras

TLDR

An optical lens can be formed by the meniscus between two immiscible liquids. The study aims to design and build a miniature achromatic camera module using the adjustable liquid lens for portable use. Electrowetting changes the meniscus curvature to vary focal distance, and lens motion during focusing was observed through the transparent tube wall. The adjustable liquid lens produces a self‑centered, high‑quality optical element, and the resulting miniature camera module performs excellently for portable applications.

Abstract

The meniscus between two immiscible liquids can be used as an optical lens. A change in curvature of this meniscus by electrowetting leads to a change in focal distance. It is demonstrated that two liquids in a tube form a self-centered lens with a high optical quality. The motion of the lens during a focusing action was studied by observation through the transparent tube wall. Finally, a miniature achromatic camera module was designed and constructed based on this adjustable lens, showing that it is excellently suited for use in portable applications.