Formation and curvature tuning of micro lens using surface tension and hydraulic pressure assisted molding process

This study presents a novel concept for the formation of curvature micro lens and the lens-curvature tuning using the hydraulic pressure and surface tension assisted molding process. The liquid UV-curable polymer is defined by hydraulic pressure, surface tension, and molding, and then solidified by UV-light to form t he micro-lens. Merits of the process technology are: (1) initial lens curvatures defined by the polymer volume and surface tension, (2) final lens curvature is tuned by the hydraulic pressure, and (3) optical pattern (Fresnel zone) can be defined by molding. In applications, the biconvex, biconcave, and convex-concave lens, and the curved Fresnel lens are demonstrated. The lens radius of curvature R_c is varying from -0.58mm to 1.5 mm. The integration of micro-lens with magnet holder for actuation is also demonstrated.