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US 8,751,172 B2Granted
Microelectromechanical viscosity measurement devices and methods thereof
AssigneeRochester Institute of Technology
InventorsIvan Puchades, Lynn Fuller
Life of this patent
Estimating the term…
Abstract
A viscosity measurement device includes a flexible membrane, an actuation heating element, and a displacement sensor apparatus. The actuation heating element is on and spaced in from an outer periphery of the flexible membrane. The displacement sensor apparatus is coupled to the flexible membrane and measures and outputs a displacement signal representative of a viscosity of a fluid in contact with the flexible membrane.
Claims32
A viscometer system comprising:
- a viscosity measurement device comprising:
- a flexible membrane;
- a supporting structure which supports and fixes an entire outer periphery of a moveable portion of the flexible membrane;
- an actuation heating element on and spaced in from the outer periphery of the flexible membrane which provides the heat to create thermal expansion differences between the membrane and a metal plate which is in at least partial alignment with the actuation heating element;
- and
- at least one displacement sensor coupled to the flexible membrane that measures the displacement of the membrane with the metal plate and outputs a displacement signal representative of a viscosity of a fluid in contact with the flexible membrane.
3 more elements
A method of making a viscosity measurement device, the method comprising:
- providing an actuation heating element on and spaced in from an outer periphery of a flexible membrane which provides the heat to create thermal expansion differences between the membrane and a metal plate which is in at least partial alignment with the actuation heating element, the entire outer periphery of a moveable portion of the flexible membrane supported and fixed by a supporting structure;
- coupling at least one displacement sensor to the flexible membrane that measures the displacement of the membrane with the metal plate and outputs a displacement signal representative of a viscosity of a fluid in contact with the flexible membrane.
A viscometer system comprising:
- a flexible membrane;
- an actuation heating element on and spaced in from an outer periphery of the flexible membrane which provides the heat to create thermal expansion differences between the membrane and a metal plate which is in at least partial alignment with the actuation heating element;
- a driving device configured to apply a driving signal at a first frequency and substantially constant power to the actuation heating element;
- at least one displacement sensor coupled to the flexible membrane that measures the displacement of the membrane with the metal plate and outputs a displacement signal representative of a viscosity of a fluid in contact with the flexible membrane;
- and
- a viscosity computing device configured to determine and provide a viscosity of the fluid in contact with the flexible membrane based on the displacement signal, to determine from the displacement signal a resonant frequency and a quality factor in the fluid and determines and provides at least one of density or the viscosity of the fluid based on the determined resonance frequency and the quality factor, and to determine a first duration for a pulse of the driving signal which is uninfluenced by the heat dissipation characteristics of the fluid and controls the driving device to apply the driving signal with the determined pulse.
3 more elements
A method of making a viscosity measurement device, the method comprising:
- providing an actuation heating element on and spaced in from an outer periphery of a flexible membrane;
- providing at least one metal plate on the flexible membrane and at least in partial alignment with the actuation heating element;
- providing a driving device configured to apply a driving signal at a first frequency and substantially constant power to the actuation heating element;
- coupling at least one displacement sensor to the flexible membrane that measures the displacement of the membrane with the metal plate and outputs a displacement signal representative of a viscosity of a fluid in contact with the flexible membrane;
- providing a viscosity computing device configured to determine and output a viscosity of the fluid in contact with the flexible membrane based on the displacement signal, to determine from the displacement signal a resonant frequency and a quality factor in the fluid and determine and provide at least one of density or the viscosity of the fluid based on the determined resonance frequency and the quality factor, and to determine a first duration for a pulse of the driving signal which is uninfluenced by the heat dissipation characteristics of the fluid and controls the driving device to apply the driving signal with the determined pulse.
2 more elements
A viscometer system comprising:
- a flexible membrane;
- a supporting structure which supports and fixes an entire outer periphery of the flexible membrane;
- an actuation heating element on and spaced in from an outer periphery of the flexible membrane which provides the heat to create thermal expansion differences between the membrane and a metal plate which is in at least partial alignment with the actuation heating element;
- a driving device configured to apply a driving signal at a first frequency and substantially constant power to the actuation heating element;
- at least one displacement sensor coupled to the flexible membrane that measures the displacement of the membrane with the metal plate and outputs a displacement signal representative of a viscosity of a fluid in contact with the flexible membrane;
- and
- a viscosity computing device configured to determine and provide a viscosity of the fluid in contact with the flexible membrane based on the displacement signal,
- wherein the viscosity computing device is further configured to determine from the displacement signal a resonant frequency or a quality factor in the fluid and determines and provides at least one of density or the viscosity of the fluid based on the determined resonance frequency and the quality factor, and
- wherein the viscosity computing device is further configured to determine a first duration for a pulse of the driving signal which is uninfluenced by the heat dissipation characteristics of the fluid and controls the driving device to apply the driving signal with the determined pulse.
6 more elements
A method of making a viscosity measurement device, the method comprising:
- providing an actuation heating element on and spaced in from an outer periphery of a flexible membrane, an entire outer periphery of the flexible membrane supported and fixed by a supporting structure;
- providing at least one metal plate on the flexible membrane and at least in partial alignment with the actuation heating element;
- providing a driving device configured to apply a driving signal at a first frequency and substantially constant power to the actuation heating element;
- coupling at least one displacement sensor to the flexible membrane that measures the displacement of the membrane with the metal plate and outputs a displacement signal representative of a viscosity of a fluid in contact with the flexible membrane;
- and
- providing a viscosity computing device configured to determine and output a viscosity of the fluid in contact with the flexible membrane based on the displacement signal,
- wherein the providing a viscosity computing device further comprises providing a viscosity computing device further configured to determine from the displacement signal a resonant frequency and a quality factor in the fluid and determine and provide at least one of density or the viscosity of the fluid based on the determined resonance frequency and the quality factor, and
- wherein the providing a viscosity computing device further comprises providing a viscosity computing device further configured to determine a first duration for a pulse of the driving signal which is uninfluenced by the heat dissipation characteristics of the fluid and controls the driving device to apply the driving signal with the determined pulse.
5 more elements
Dependencies are inferred from the claim text.