Lorentz Force Actuated Tunable-Focus Liquid Lens

Micromachines (Basel). 2019 Oct 22;10(10):714. doi: 10.3390/mi10100714.

Abstract

Tunable-focus liquid lenses provide focal length tuning for optical systems, e.g., cameras, where physical movement of rigid lenses are not an option or not preferable. In this work we present a magnetically actuated liquid lens utilizing the Lorentz force to vary the focal length as the current through the system is varied. The resulting lens can operate as both a diverging and a converging lens depending on the direction of current applied and has a large range of focal lengths, from -305 mm to -111 mm and from 272 mm to 146 mm. We also characterized the aberrations of the lens during the actuation with a Shack-Hartmann wavefront sensor, and utilized the lens for imaging, during which we measured a resolution of 7.13 lp/mm.

Keywords: liquid lens; magnetic actuator; optofluidics; tunable lens.