From Liquid Crystals: Frontiers In Biomedical Applications

John W. McMurdy, Gregory P. Crawford and Selim Suner

We have all the light we need, we just need to put it in practice.

Albert Pike

Biomedical spectroscopy and imaging are tools heavily relied upon in the scope of both clinical diagnostics and research. Liquid crystal devices such as variable retarders, waveplates, and filters have been integrated into spectrometers and imaging systems for a variety of different reasons. Liquid crystal devices have the potential to increase system functionality, improve accuracy, and increase acquisition speeds while reducing system size and cost. The properties of this broad grouping of liquid crystal devices lends to applications primarily in ultraviolet/visible/near infrared absorption spectrometers, hyperspectral imaging systems, phase contrast microscopes, and polarimeters/polarimeric imaging systems. The application of liquid crystal technology in each of these spheres is discussed along with a brief summary of current biomedical applications and research foci of each respective technique.

3.1 Introduction to Biomedical Spectroscopy and Microscopy

Biomedical spectroscopy, in one shape or form, is one of the most utilized and underutilized tools in biology; utilized in the sense that many biomedical spectroscopy techniques have been adopted as viable clinical and research tools, and underutilized in that there are many exciting applications of biomedical spectrosopy not yet explored. When examining the breadth of topics under the umbrella of biomedical spectroscopy, which may include near-infrared (NIR) imaging, visible/ultraviolet (UV/Vis) absorption spectroscopy, opto-acoustic spectroscopy, polarimetry, scattering spectroscopy, x-ray scattering, flow cytometry, Raman/FTIR vibrational imaging/spectroscopy, surface plasmon resonance, fluorescent imaging (

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Topics of Interest

3.2 Diffraction Gratings and Tunable Filter Spectrometers A light source can be decomposed into its spectral constituents by either dividing the spectrum over space in a dispersive configuration or...

3.6 Conclusion The implications and applications of liquid crystals in spectroscopy and microscopy are quite broad, as is evidenced by the sheer range of topics highlighted in this chapter.

3.4 Polarimeters and Polarization Microscopy Polarimeters are devices used to measure the polarization state of light after sample interaction; useful in characterizing interactions beyond...

Bibliography Acharya, B. R., Madsen, C. K., Baldwin, K. W., MacHarrie, R. A., Rogers, J. A., Moller, L., Huang, C. C. and Pindak, R. (2003). In-line liquid-crystal microcell polarimeter for...

Table 1.1: Properties of Materials and Methods of Analysis Property Method of Analysis Color OM(S/B) Virtual image and magnification OM(S) High topological magnification EWS) Subsurface...