Multipurpose DVD pick-up scanner for analysis of microfluidics and micromechanical structures

Microfluidics has become increasingly prevalent and has founded widespread use in various applications such as biomedical applications (diagnostics, therapeutics, and cell/tissue engineering), inkjet head, and fuel cells etc. The issue of inspection and characterization of microfluidics has emerged as a major consideration in design, fabrication, and optical detection of devices. In this paper, we characterize the mixing flow pattern by diffusion, when two flows are combined in microchannel, using an optical scanner based on a DVD pick-up module, which is widely used in optical storage. Using Cy5.5 dye, we measure the fluorescent intensity that represents fluidic characteristics in Y-microchannel with 1 μm resolution and compare experimental results with computational fluid dynamics (CFD) simulation ones. Si based microstructures are measured using different optical reflective paths to the optical scanner with respect to the surface topologies. It is shown that the proposed optical scanner can be effectively and versatilely used to observe microfluidic characteristics and to measure the surface profiles of microstructures, being a cost-effective alternative device to conventional epifluorescent microscopes using high resolution CCD camera and interferometers.