Electronic Thesis and Dissertation Repository

Degree

Master of Engineering Science

Program

Mechanical and Materials Engineering

Supervisor

Dr. George K. Knopf

Abstract

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.