Focal point control using an EWOD-based tuneable Fresnel lens

This work presents focal tuning of Fresnel lens using arrayed liquid prisms via electrowetting-driven beam steering. Liquid prism arrays are individually controlled to mimic small subsections of a Fresnel lens. Arrayed subsections in the proposed device are symmetrically tuned to achieve focal length control, while conventional solid-type Fresnel lenses provide a fixed focal length. Consequently, incoming light beams can be effectively converged at a single point in space without any bulky mechanical moving parts.