SBIR Phase I: Microfluidic Gas/Liquid Two-Phase Sensing and Compensation

This Small Business Innovation Research Phase I research project addresses research and development into two-phase microfluidic behavior in resonating microtubes. Gas phase, or air bubble detection in intravenous drug lines is critical to preventing air embolisms and even death. Two-phase detection and damping problems have been reported in macroscopic Coriolis mass flow meters and in MEMS-based resonant tubes. There are experimental indications that microbubbles may be nucleating ultrasonically and then growing while attached to the interior of microfluidic resonant tubes. It is proposed to utilize resonant microtube technology to investigate the impact of gas phase formation and the gas liquid interaction and compensation for the associated damping as it applies to Coriolis mass flow and density measurement. This innovative research will improve bubble detection in liquid medication delivery systems and overcome problems experienced with two-phase damping in resonant sensing systems. The initial test bed will be for a MEMS-based, microfluidic drug delivery system. A new method of performing cell lysis and DNA analysis on small samples may be realized if cavitation can be controlled in the microtubes. The final goal is to successfully enable the commercialization of microfluidic Coriolis mass flow sensors and chemical concentration meters for industrial and medical applications. For this to happen the problems associated with gas phase detection and the two-phase damping must be overcome. This research has the potential of introducing a new means of detecting and measuring a second, gas phase in a liquid stream.