Fabrication and characterization of microlenses realized by a modified LIGA process

Ruther, Patrick; Gerlach, Barbara; Göttert, J.; Ilie, Mihaela; Mohr, Jürgen; Müller, André; Ossmann, Christian

doi:10.1088/0963-9659/6/6/006

Cited by 52 publications

(32 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Molding and casting optical materials are very common [4][5][6]: In these techniques, the fabrication of a template has to be accomplished previous to the manufacturing of the microlenses. For template production, various techniques such as photolithography [7], ion exchange [8] or LIGA processes [9] are used. Arrays of microparticles have been used recently as template to fabricate microlenses [4,10], as well as irradiation of sol-gels with UV light [11].…”

Section: Introductionmentioning

confidence: 99%

Arrays of microlenses with variable focal lengths fabricated by restructuring polymer surfaces with an ink-jet device

Pericet-Cámara¹,

Best²,

Nett³

et al. 2007

Opt. Express

View full text Add to dashboard Cite

Abstract:We report of a method for fabricating two-dimensional, regular arrays of polymer microlenses with focal lengths variable between 0.2 and 4.5 mm. We first make concave microlenses by ink-jetting solvent on a polymer substrate with a commercial drop-on-demand device. Solvent evaporation restructures the surface by a series of combined effects, which are discussed. In the second step we obtain convex elastomeric microlenses by casting the template made in the first step. We demonstrate the good optical quality of the microlenses by characterising their surfaces with atomic force microscopy and white light interferometry, and by directly measuring their focal lengths with ad-hoc confocal laser scanning microscopy.

show abstract

Section: Introductionmentioning

confidence: 99%

Arrays of microlenses with variable focal lengths fabricated by restructuring polymer surfaces with an ink-jet device

Pericet-Cámara¹,

Best²,

Nett³

et al. 2007

Opt. Express

View full text Add to dashboard Cite

show abstract

“…M ICROLENSES are key elements in optical microsystems and the majority of them are made of plastic materials in common MEMS (Microelectromechanical Systems) applications. Previously, attempts were made to fabricate threedimensional (3-D) lenses with different micromachining techniques, including lithographic methods [1], [2], reflow of photoresist [3] and isotropic etching of silicon as mold inserts for the plastic molding processes [4], [5]. Surface roughness and the controllability of radius of curvature of the microlens are two major engineering challenges.…”

Section: Microplastic Lens Array Fabricated By a Hot Intrusion Processmentioning

confidence: 99%

Microplastic Lens Array Fabricated by a Hot Intrusion Process

Pan

Shen

Lin

2004

J. Microelectromech. Syst.

View full text Add to dashboard Cite

A microplastic lens array has been successfully constructed on top of a 500-m-thick PC (Polycarbonate film) by using a micro hot intrusion process. A single-layer LIGA process is used to fabricate the high-aspect-ratio nickel mold insert that has circular hole patterns of 80 m in diameter and 200 m in depth. Under the hot intrusion process, plastic material can be intruded into these circular-shape holes and stopped at desired depth under elevated temperature and pressure to fabricate microlenses. By adjusting the embossing load, temperature and time, the curvature and height of the lens are controllable when the same mold insert is used. The optical properties of these microlenses have been characterized and the average radius of curvature is found as 41.4 m with a standard deviation of 1.05 m. Experimental characterization and theoretical model are conducted and developed for the micro-intrusion process in terms of the radius of curvature and height of the lenses and they correspond well with experimental data within 5% of variations. The focusing capability of the lenses is demonstrated by comparing the images of laser light with and without using the lenses. When the projection screen is placed 200 m away from the lens, the full-width at half-maximum (FWHM) for the lens is 110 m while the original FWHM of the optical fiber is 300 m.[1201]

show abstract

“…Microlenses and microlens arrays are essential elements not only for the practical applications but also for the fundamental studies in the microoptics. There have been several fabrication methods for microlenses or microlens arryas such as a modified LIGA process [1], photoresist reflow process [2], UV laser illumination [3], etc. And the replication techniques, such as injection molding, compression molding [4] and hot embossing [5], are getting more important for a mass production of microoptical products due to the cost-effectiveness.…”

Section: Introductionmentioning

confidence: 99%

Replication of microlens arrays by injection molding

Lee

Kim

Kwon

2004

Microsystem Technologies

111

View full text Add to dashboard Cite

Injection molding could be used as a mass production technology for microlens arrays. It is of importance, and thus of our concern in the present study, to understand the injection molding processing condition effects on the replicability of microlens array profile. Extensive experiments were performed by varying processing conditions such as flow rate, packing pressure and packing time for three different polymeric materials (PS, PMMA and PC). The nickel mold insert of microlens arrays was made by electroplating a microstructure master fabricated by a modified LIGA process. Effects of processing conditions on the replicability were investigated with the help of the surface profile measurements. Experimental results showed that a packing pressure and a flow rate significantly affects a final surface profile of the injection molded product. Atomic force microscope measurement indicated that the averaged surface roughness value of injection molded microlens arrays is smaller than that of mold insert and is comparable with that of fine optical components in practical use.

show abstract

Fabrication and characterization of microlenses realized by a modified LIGA process

Cited by 52 publications

References 1 publication

Arrays of microlenses with variable focal lengths fabricated by restructuring polymer surfaces with an ink-jet device

Arrays of microlenses with variable focal lengths fabricated by restructuring polymer surfaces with an ink-jet device

Microplastic Lens Array Fabricated by a Hot Intrusion Process

Replication of microlens arrays by injection molding

Contact Info

Product

Resources

About