MEMS for pressure distribution studies of gaseous flows in microchannels

Abstract

The first ever experimental data on the pressure distribution of gaseous flows in micron-sized channels (microchannels) is successfully obtained. This is achieved by using our newly developed microflow MEMS systems that consist of both microchannels and distributed pressure sensors. Two type of microchannels are developed. One is a straight channel with a uniform cross section, and the other has a variable cross section with Venturi-meter-like transitions. It is discovered that gaseous pressure distributions in microchannels are not linear. Moreover, it is also discovered that transitions in microchannels can result in either pressure drops or rises depending on their geometry. The Navier-Stokes equation with slip boundary conditions has been solved to model the gas flow in microchannels with uniform cross-sectional area. It is found that the model (first used by Arkilic et al., 1994) can fit the experimental data. One interesting phenomenon found in both microflow systems is that the pressure gradients near the inlet and outlet are very small. Such a phenomenon, however, can not be explained by this slip flow model.