Patent ID: 8020432

Claim:
An acoustic micro-electromechanical viscometer, comprising: a chamber is filled with a measurand viscous fluid; said viscous fluid having a given penetration depth, δ, a given viscosity, η, and a given mass density, ρ; said chamber having a rigid, planar non-resonating boundary, a means for lateral movement to adjust said boundary, and a sealable lid; a resonator, having at least one resonator surface, is positioned inside said chamber at a predetermined separation distance, l, between said boundary and said resonator surface, said resonator surface being parallel to said boundary; said predetermined separation distance being comparable to said given penetration depth, defines a thin layer of said viscous fluid between said resonator surface and said boundary; a means for monitoring viscosity; and said resonator being driven at a selected frequency generates an evanescent shear mode wave in said viscous fluid causing a mechanical admittance and a mechanical impedance in said thin layer allowing said monitoring means to measure said given viscosity independently from said given mass density at an increased level of accuracy.