BEHAVIOR OF MICROFLUIDIC AMPLIFIERS

Two types of microfluidic amplifiers (wall-attachment and jet-deflecti on) have been implemented in silicon using standard micromachining met hods and anodic sealing with a glass cap. The devices have areas of ap proximately 1 mm X 0.5 mm and the complete structures with interconnec tion channels have areas of 12 or 18 mm X 6 mm. Flow control and flow gain are demonstrated with supply pressures ranging up to 630 kPa, usi ng dry nitrogen as the test fluid. An asymmetric output flow is observ ed from the two output ports at sufficiently high supply pressures in both devices, suggesting possible shock-wave formation. The jet-deflec tion microfluidic amplifier presents a more symmetric behavior and pro vides higher flow variation than the wall-attachment device. The ratio of the maximum and minimum output flows, as measured for the jet-defl ection device for various control and supply pressures, reveals a perf ormance degradation at the onset of choked supply flow.