Electronic Thesis and Dissertation Repository


Master of Engineering Science


Mechanical and Materials Engineering


Dr. George Knopf, Dr. Evgueni Bordatchev


Large surface area, thin, polymer optical waveguides are an emerging technology that enable a wide variety of light collection and illumination systems to be created for passive lighting, solar collectors, and safety lighting for motorized vehicles. This research builds on design of rigid concentrator and diffuser waveguides, proposing and evaluating modifications for the design of a flexible waveguide combining both concentrating and diffusing functionalities. The waveguides are thin, mechanically flexible sheets with thicknesses in the range of mm, and active surfaces from a few cm2 to several m2. Regions of the functional surface are designed to act as light concentrators, light diffusers, light transmission conduits or some combination thereof. This research examines how the geometry and spatial distribution of micro-optical features patterned on a bi-layered thin polydimethylsiloxane (PDMS) waveguides can be used to guide captured light rays through flat and flexible configurations. Zemax OpticStudio software simulation tool is used to investigate the design parameters and their impact on concentrator and diffuser performance. A multi-functional concentrator-diffuser waveguide is modelled and analysed in a study which shows the flat waveguide has an overall efficiency of over 94%, however when it is modelled as a flexible waveguide, less than 1% of the incident light is successfully guided. Various design modifications are considered to mitigate these losses, and the efficiency of the flexible waveguide is improved to nearly 60%. Based on the parametric optimization of the microfeatures, the suitable waveguide design is identified for variations in the waveguide’s flexibility, geometry, material and application.