Embodiments of the present invention are directed to a MEM viscosity
sensor that is configured to be operated submerged in a liquid. The MEMS
viscosity sensor comprises a MEMS variable capacitor comprising a
plurality of capacitor plates capable of being submerged in a liquid. An
actuator places a driving force on the variable capacitor which causes
relative movement between the plates, where the movement creates a shear
force between each moving plate and the liquid, which damps the movement
of the plate and increases the capacitor's response time to the applied
force in accordance with the liquid's viscosity. To determine the actual
viscosity of the liquid, a sensor is coupled to the variable capacitor
for sensing the response time of the plates as an indicator of the
liquid's viscosity.