Abstract

Lab-on-a-chip devices are changing the way that medical testing is performed by allowing rapid testing with small samples. Optofluidic biosensors are a type of lab-on-a-chip device that use light excitation on a fluid sample. One such application of an optofluidic biosensor is a device that can detect antibiotic resistant bacteria by combining DNA from a sample with fluorescent beads, flowing that sample through a hollow channel, and shining laser light on the channel. If the bacteria tested for is present, the fluorescent beads will give off photons that can be detected as a positive signal. The main method for illumination for these devices has been coupling light through a fiber optic cable to a waveguide on the side of the chip. Though effective, this method is impractical in a real world setting such as a hospital due to the difficulty of aligning to the side of the device. One solution to this problem is the use of illumination from the top of the device. Top-down illumination allows for more alignment flexibility, but also introduces the risk of additional noise or false signal as extra light reflects of the device. This dissertation discusses the viability and development of top-down illumination for optofluidic biosensors. This includes the development of an anti-reflective layer compatible with optofluidic biosensors, comparison of top-down illumination to side illumination, and simulations of various methods of performing top-down illumination. Based on the research and findings discussed in this dissertation, it has been found that top-down illumination is a viable illumination method for optofluidic biosensors. Additionally, the use of a pattern of laser lines combined with a light blocking anti-reflective layer is the recommended method for top-down illumination.

Degree

PhD

College and Department

Electrical and Computer Engineering

Rights

https://lib.byu.edu/about/copyright/