Coriolis mass flow sensors are based on the measurement of the Coriolis forces that act on the fluid flowing through a vibrating tube. Their key advantage over other types of mass flow sensors is that they provide a direct measure of mass flow, independent of fluid parameters like density, viscosity and thermal conductivity. The aim of this project is to realize a compact and reliable mass flow sensor whose resolution is only limited by the random thermal motion of the vibrating sensor tube. This will be accomplished by combining an optimized sensor design with CMOS readout electronics. The final aim is a TRL6 prototype consisting of two chips: one for the vibrating sensor tube and another for the CMOS readout electronics.