Tunable-focus liquid lens controlled using a servo motor

TLDR

The lens is built from an elastic membrane, glass plate, sealing ring, and fixed‑volume liquid, with a hollow reservoir linked to the chamber; a servo‑motor shaft deforms the rubber membrane, forcing liquid into the chamber and changing the membrane shape to adjust focal length. Its compact structure and straightforward actuation make it suitable for zoom lenses, auto beam steering, and eyeglasses.

Abstract

We demonstrated a liquid lens whose focal length can be controlled by an actuator. The lens cell is composed of elastic membrane, planar glass plate, a periphery sealing ring, and a liquid with a fixed volume in the lens chamber. Part of the periphery sealing ring is excavated to form a hollow chamber which functions as a reservoir. This hollowed periphery is surrounded by an exterior rubber membrane. The shaft of an actuator is used to deform the elastic rubber. Squeezing the liquid contained in the reservoir into the lens chamber. Excess liquid in the lens chamber will push the lens membrane to outward, resulting in a lens shape change. Due to the compact structure and easy operation, this liquid lens has potential applications in zoom lenses, auto beam steering, and eyeglasses.