Electronic Thesis and Dissertation Repository


Master of Engineering Science


Mechanical and Materials Engineering


Dr. George K. Knopf


Mechanically flexible large area polydimethylsiloxane (PDMS) optical devices are fabricated using soft-lithography techniques based on replica moulding. These non-rigid optical devices can be designed as sheets to act as either light concentrators (collectors) or diffusers (illuminators) based on the position and geometry of micro-optical structures (MOSs) embedded within the sheet or imprinted on its surface. The active surface area of the device can range from less than a sq. cm to several sq. m. The performance of the large area optical device is a function of the location and geometry of micro-optical structures, thickness and shape of the flexible waveguide, core and cladding material (ie. refractive indices), and the wavelength of the incident light source. A centrifugal casting technique that simultaneously de-gasses and fills a patterned, thin mould cavity is introduced as the backbone to the proposed fabrication methodology. Combined with the ability to control the refractive index of PDMS and a partial curing technique that bonds subsequent layers, a bottom-up layer-by-layer fabrication process is proposed and described in detail.