Fabrication method for microfluidic channels with circular cross section for micro-Coriolis mass flow sensor

This paper presents a new fabrication method to realize a channel underneath the surface of a single silicon substrate for micro Coriolis flow sensing application, as well as other multiparameter systems, such as thermal flow sensors. It allows to fabricate channels with a nearly perfect circular cross section without bonding of two wafers. With this technology, problems such as leakage, deformation of channels due to pressure and temperature that affect the performance of micro Coriolis flow sensor can be reduced significantly. Moreover, it leaves only very little topography on the surface of substrate, hence integration of actuation and readout systems by metal deposition can still be followed easily afterwards.