title: Micromachined Fused Silica Liquid Core Waveguide Capillary Flow Cell.
abstract: A planar, chip-based flow cell for UV-vis absorbance detection in HPLC is presented. The device features a microfabricated free-standing liquid core waveguide (LCW) capillary detection tube of long path length that is based on total internal reflection. We report on the linearity and calibration slope characteristics of lithographically produced LCWs with different interior/exterior geometries. 3D ray tracing was indispensable in modeling behavior in the more demanding geometries: multipath behavior may be intrinsic to these waveguides with consequent nonlinearity. Fortunately, nonlinearity in lithographically easy-to-produce waveguide geometries (such as with a flat, concave exterior and a round interior) is not as detrimental as might be initially expected. Experimental performance is predictably affected by the attainable surface quality of the LCW and efficient and reproducible coupling of the input light into the LCW.
authors.affiliation: Agilent Technologies , Hewlett-Packard Strasse 8, D 76337 Waldbronn, Germany.|IMTEK-Department of Microsystems Engineering, University of Freiburg , D-79110 Freiburg, Germany.
authors.forename: K G
authors.initials: KG
authors.lastname: Kraiczek
authors.affiliation: Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States.
authors.forename: J
authors.initials: J
authors.lastname: Mannion
authors.affiliation: Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States.
authors.forename: S
authors.initials: S
authors.lastname: Post
authors.affiliation: Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States.
authors.forename: A
authors.initials: A
authors.lastname: Tsupryk
authors.affiliation: Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States.
authors.forename: V
authors.initials: V
authors.lastname: Raghunathan
authors.affiliation: Agilent Technologies , 5301 Stevens Creek Boulevard, Santa Clara, California 95051, United States.
authors.forename: R
authors.initials: R
authors.lastname: Brennen
authors.affiliation: IMTEK-Department of Microsystems Engineering, University of Freiburg , D-79110 Freiburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Zengerle