Realization and characterization of SU-8 micro cylindrical lenses for in-plane micro optical systems

Abstract

This study presents a new method of fabricating and integrating micro cylindrical lenses (MCLs) into an inplane micro optical system. The characterizations of MCLs, which are made of SU-8 negative photoresist, are also reported in this study. Many demands, especially for arbitrary lens shapes and accurate alignment, can be met by the proposed method. The measurements of size revealed that SU-8 MCLs swelled, but the amount of swelling maintained constant for at least six months. Two factors were demonstrated to govern the swelling of SU-8 structures, and can be compensated for in the design of the mask. The SU-8 MCLs are shown to exhibit function with a satisfactory optical property. Fluorescence is collimated and focused in a micro channel, demonstrating the potential of MCLs to detect laser-induced-fluorescence (LIF). The fluorescence behavior of SU-8 is also examined herein. The advantages of rapid prototyping and easy integration of SU-8 MCLs have a range of many applications, especially in in-plane micro optical configurations.

Advances in Polymer-Based Optical MEMS Fabrication for VCSEL Beam Shaping

“…SU-8 is indeed transparent over the visible and near infra-red ranges with absorption losses lower than 3 dB/cm [40]. SU-8 has been fruitfully exploited for the fabrication of organic waveguides, micro-resonators [41] and microlens arrays [42]. Additionally, the integration of SU-8-based microlenses on VCSELs has been reported, taking advantage of the properties of SU-8 cylindrical pedestals [43], [44].…”

Planar lens integrated capillary action microfluidic immunoassay device for the optical detection of troponin I

“…Various light delivery and focusing components ranging from planar/3D lenses [3][4][5][6][7][8][9][10][11][12] to waveguides 13,14 have been demonstrated in integrated microfluidic and lab-on-a-chip devices. The primary advantages to such on-chip integration, in addition to the reduced size of key optical elements, are the self-alignment of the components and the ability to more tightly focus light onto microfluidic channels.…”

“…Of all the demonstrated strategies, planar light guiding structures have demonstrated a high efficiency for light focusing within microsystems, with greatly reduced overall design complexity and modest increases in the total device footprint. [3][4][5][6][7][8][9][10]12 In the work conducted by Seo et al, for example, significant consideration was paid to complete device miniaturisation, where a disposable format was created that operated directly from an LED excitation source, with no additional devices required for light coupling. 9 Additionally, it was found that 2D Polydimethylsiloxane (PDMS) based microlenses confined the excitation emission within the chip and yielded no detectable excitation light orthogonal to the chip plane, resulting in a 7-fold increase in the detected fluorescence intensity from a sample of fluorescent nanospheres.…”

Optical simulation, design, and optimization of a microchip-based flow cytometer

“…Microchip-based flow cytometry has seen a large amount of interest in recent years with many works done to fabricate simple and inexpensive devices in a single plane on a single wafer using inserted fibres or integrated waveguides [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], liquid core waveguides [17,18], incorporated microoptical elements, such as lenses, mirrors, tapers [19][20][21][22][23][24][25][26][27]. Devices have even been made that incorporate an excitation source and detections sources on the same chip as the microfluidics [28,29].…”