A Comprehensive Study and Optimization of Nozzle-Diffuser Valves for Reciprocating Micropumps
Sprache des Titels:
Proceedings of the 2nd European Conference on Microfluidics
Microfluidic valves using a combination of nozzles and diffusers have been of great interest and found many applications in microfluidic devices especially in reciprocating micropumps since the late 1990s. This interest results from their relatively simple design which does not require any moving parts facilitating a fast and easy manufacturing process. Furthermore, they are suitable for low cost fabrication. The functionality of these valves is based on the hydrodynamic effect that a diffuser (i.e., a channel with diverging walls) has a lower hydraulic resistance than a nozzle (i.e., a channel with converging walls) and thus favors one flow direction. This fact has already been observed and reported but has not been explained in detail particularly for the case of micro-channels. To this end, a study of micro nozzle-diffuser valves is presented in this contribution. We used an analytical approach to be able to explain the functionality of these valves. The associated results are compared to those obtained with an FE-analysis and an experimental investigation, both confirming the findings from the analytical approach.