• Login
    View Item 
    •   DSpace@RPI Home
    • Rensselaer Libraries
    • RPI Theses Online (Complete)
    • View Item
    •   DSpace@RPI Home
    • Rensselaer Libraries
    • RPI Theses Online (Complete)
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Dynamic beam shaping using electrowetting effects

    Author
    Zhang, Zhen
    View/Open
    177094_Zhang_rpi_0185E_10755.pdf (23.37Mb)
    Other Contributors
    Karlicek, Robert F.; Jensen, M. K.; Borca-Tasçiuc, Theodorian; Chung, Aram; Plawsky, Joel L., 1957-;
    Date Issued
    2015-12
    Subject
    Mechanical engineering
    Degree
    PhD;
    Terms of Use
    This electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.;
    Metadata
    Show full item record
    URI
    https://hdl.handle.net/20.500.13015/1628
    Abstract
    A geometric model was developed to describe the meniscus shape of a rectangular electrowetting lens under arbitrary voltages for small Bond numbers. The model assumes the meniscus being a part of a toroidal surface. Seven variables (cell width, cell length, the saline solution volume, and the four contact angles on the four sidewalls) determine the meniscus shape. From the model, the optical parameters of the two primary radii of the meniscus and its optical tilt and pan angle can be obtained.; Based on the toroidal model, ray tracing analyses were conducted on single electrowetting lenses and lens arrays. The largest beam angle change and tilt angle change were 0-16.7 degrees and 0-9.3 degrees, which were too small to be useful for a dynamic optical beam shaper. The effects of refractive index, cell size, and cell numbers were studied, the findings of which led to an enhancement design with different geometry and a secondary lens array. The beam angle control range improved to 4.7-49.9 degrees. The beam tilt angle control range increased to 0-35.5 degrees. Although the optical efficiency dropped by 14-15%, the enhancement design demonstrated that electrowetting is a good candidate for a dynamic optical beam shaper.; Experimental validation of the geometric model was conducted by comparing the dynamic image shifts of a wire mesh produced with suitably designed electrowetting cells and the corresponding image obtained through ZEMAX image simulation. The experimental 2 × 2 × 12.7 mm rectangular electrowetting cells were fabricated and used as test samples for experimental validation. Focal length change, radius of one primary curvature change, tilt meniscus along one sidewall, and tilt meniscus along diagonal direction were studied. The model prediction had an excellent match with the first two cases. For the latter two cases, the model predicted the general trend and shape but under-predicted optical changes at the corners of the experimental cells.; The model was compared with the Surface Evolver simulation, which obtained the meniscus shape via energy minimization. The difference between the geometric model and the energy minimizing simulation is calculated. The largest standard deviation of the differences over cell widths is less than 2%.; The applicability of the electrowetting technology on dynamic beam shaping in lighting applications is demonstrated in this study.;
    Description
    December 2015; School of Engineering
    Department
    Dept. of Mechanical, Aerospace, and Nuclear Engineering;
    Publisher
    Rensselaer Polytechnic Institute, Troy, NY
    Relationships
    Rensselaer Theses and Dissertations Online Collection;
    Access
    Restricted to current Rensselaer faculty, staff and students. Access inquiries may be directed to the Rensselaer Libraries.;
    Collections
    • RPI Theses Online (Complete)

    Browse

    All of DSpace@RPICommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    Login

    DSpace software copyright © 2002-2022  DuraSpace
    Contact Us | Send Feedback
    DSpace Express is a service operated by 
    Atmire NV