Design and fabrication of a copolymer aspheric bi-convex lens utilizing thermal energy and electrostatic force in a...

The purpose of this paper is to use thermal energy and electrostatic force as an alternative to high-cost precision cutting or traditional injection molding in the fabrication of COC (cyclo-olefin copolymer) plastic aspheric bi-convex lenses with high Blu-Ray transmittance (92% at 405 nm). A glass substrate was used, and ultrasonic drilling defined the clear aperture of the aspheric bi-convex lens. The copolymer lens material was measured, filled and melted into the hole. A gradient electrical potential was applied between the top and bottom electrodes of the COC liquid droplet to control the profile of the lens. The thermal energy melted the COC into a dynamic fluid, and the electrostatic force controlled the aspheric morphology of the designed profile. The resulting lenses have a clear aperture of approximately 1.14 mm and a front focal length of 4.97 mm, and the spot size of the fabricated aspheric bi-convex lenses can be controlled to approximately 0.588 microm. This technology is capable of fabricating lenses for application in micro-optical systems.