Patent ID: 7823445

Claim:
A fluid sensing system adapted to be placed in a flowing fluid for sensing properties thereof, the fluid sensing system comprising: a microfluidic device comprising a micromachined tube supported above a substrate so as to define a gap therebetween, a tube passage within a freestanding portion of the micromachined tube, an inlet and outlet in fluidic communication with the tube passage and an exterior of the microfluidic device, means for vibrating the freestanding portion of the micromachined tube at a resonant frequency thereof, and means for sensing movement of the freestanding portion of the micromachined tube so as to measure at least one of the vibration frequency and deflection of the freestanding portion relative to the substrate and produce therefrom at least one output corresponding to at least one of the mass flow rate, specific gravity, and density of a fluid flowing through the tube passage; means for placing the microfluidic device in a flowing fluid so that a fraction of the fluid enters the tube passage of the micromachined tube through the inlet of the microfluidic device; and means for processing the at least one output to compute a property of the fluid.