Page 259 - Optofluidics Fundamentals, Devices, and Applications

Bio-Inspir ed Fluidic Lenses for Imaging and Integrated Optics 233

These devices are generally made up of bulk optics and can easily
take up an entire tabletop, though some smaller versions do exist.
Miniaturization of the flow cytometer would allow for point-of-
care testing, testing in rural areas lacking infrastructure for a perma-
nent clinic, or in-the-field testing of samples ranging from blood to
water sources. Much of the work referred to in this section involves
some form of lab-on-a-chip approach to flow cytometry. Over the
years, these systems have grown in complexity from simple fiber-
against-channel approaches to approaches integrating lenses and
other optical elements to create a sophisticated system on a chip
[83,84,86,93,104]. As the field of on-chip optics progresses, more opti-
cal elements are added to the “toolbox” for creating lab-on-a-chip
devices, enabling higher quality systems to be created. Figure 9-24
shows a prototype lab-on-a-chip cytometer integrating fibers,
waveguides, lenses of various shapes and sizes, and beam blocks.
Figure 9-25 shows a parabolic lens. Figure 9-26 shows a beam block,

FIGURE 9-24 A prototype lab-on-a-chip cytometer, consisting of an illumination
line, two scatter collection lines (all highlighted in blue), and a large numerical
aperture fl uorescence collection line (highlighted in red). This compact, highly
integrated device is manufactured by simple molding techniques. (J. Godin,
C.-H. Chen, S. H. Cho, W. Qiao, F. Tsai, and Y.-H. Lo, “Microfl uidics and
photonics for Bio-System-on-a-Chip: A review of advancements in technology
towards a microfl uidic fl ow cytometry chip,” Journal of Biophotonics 2008.
Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.)