Microlens rapid prototyping technique with capability for wide variation in lens diameter and focal length

• Published in: Microelectronic engineering Vol. 87; no. 11; pp. 2376 - 2381
• Main Authors: Cruz-Campa, J.L., Okandan, M., Busse, M.L., Nielson, G.N.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2010; Elsevier
• Subjects: Computer programs; Cross-disciplinary physics: materials science; rheology; Curvature; Deposition; Exact sciences and technology; Lenses; Materials science; Mathematical analysis; Mathematical models; Microlenses; Other materials; Physics; Polymer; Rapid prototyping; Specific materials; Surface tension; Microlenses; Polymer; Rapid prototyping; Surface tension; Spherical shape; Computer software; Focal length; Contact angle; Empirical model; Hardening; Rapid technique; Temperature effects; Polymers; Curvature; Profilometry
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2010.04.012

A “mold-less” method for rapid prototyping spherical microlenses using the surface tension of a transparent, temperature sensitive polymer is presented. The lens size can be varied with the volume of the polymer dispensed, with a diameter range of 450 μm–4 mm. The focal length can be varied with the deposition/curing temperature, and can have values in the range of 2–25 mm. Mechanical profilometry and custom software was used to measure the lens profile. Parameters such as curvature, focal length, diameter, contact angle, and F-number were extracted from the measurements. Finally, an empirical model that predicts these variables as a function of temperature and volume deposited is proposed.