UC San Diego

Microfluidics is a quickly expanding field with numerous applications. The advent of rapid-prototyping and soft- lithography allow for easy and inexpensive fabrication of microfluidic devices. Fluid manipulation on the microscale allows for new functionalities of devices and components not available on the macroscale. Fluid flows on the microscale are laminar with chemical mixing defined strictly by diffusion allowing us to design microfluidic devices with precise control of fluid flow and chemical concentration. New microfluidic technologies can provide new functionalities for micro-total analysis systems for greater device integration and portability. To expand the utilization of microfluidics, this dissertation discusses new microfluidic techniques and devices. Chapter 2 examines microfluidics for quantitative cell biology. New techniques discussed in this dissertation allow us to use microfluidics to study cellular response on a cell-by-cell basis in stable environments. Part of this chapter includes new architectures for creating chemical concentration gradients in microfluidic devices and their applications cell biology. The rest of Chapter 2 introduces a device which allows for cells to grow to high densities in chemostatic conditions. Chapter 3 introduces the merger of optics and microfluidics named "optofluidics". This subset of microfluidics uses the techniques and materials of microfluidics for optical applications. This dissertation describes optofluidic projects involving light manipulation such as a switch, actuator and lens