Characterization Of A Microfluidic Bubble Removal System Using A Converging-Diverging Nozzle

Undesired bubble formation has been a major problem in microfluidics devices. Depending on the application, air bubbles can affect the performance of microfluidic devices and lead to failure. Recent microfabrication techniques have originated several approaches in order to solve this problem such as bubble traps and debubblers. However, these methods require large equipment and long periods of time to remove air bubbles. In this thesis, a microfluidic vacuum source is used and characterized in order to remove air bubbles in a non-invasive way. This miniaturized vacuum source is based on a converging-diverging nozzle device which is able to generate a range of negative pressures, depending on the input flow of a pressurized gas tank. It was found that the microfluidic converging-diverging nozzle can achieve a vacuum pressure of -7.23 psi which corresponds to a bubble extraction rate of 9.84 pL/s using our network model device. In addition, this bubble removal system was applied on devices that contain partially filled channels due to its structure design. Finally, future improvements to this bubble removal system are discussed as well as the benefits of this system compared to other approaches.