Peristaltic piezoelectric pump with internal load sensor
AssigneeThe Abet Group
InventorsJohn B. Beckman, Martin J. Blickstein
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Abstract
An apparatus for pumping a fluid by means of a piezoelectric pump is provided. All moving parts, including the valves and core, are piezoelectrically motivated. The preferred embodiment includes a piezoelectric ceramic tube having conductive bands adhered to the outer surface. The conductive bands and an inner surface electrode define tube regions which serve as valve and reservoir pump regions. A sensing circuit senses the voltage on the outer electrodes of the innermost of the piezoelectric regions to detect the presence of faulty pumping operation. The sensing circuit utilizes the piezoelectric effect that results from internal loading of the core.
Claims18
A piezoelectric pump comprising:
- a plurality of piezoelectric tube regions, each said region having an outer surface and an inner surface defining a cavity;
- an electrode associated with each said outer surface and inner surface for applying electric signals to said surfaces;
- means for selectively phasing said electrical signals such that said regions expand and contract in a peristaltic motion to pump fluid through said cavity;
- and
- means for sensing the piezoelectric effect that results from the internal load on the innermost of said piezoelectric tube regions.
A piezoelectric pump, comprising:
- an inner cylindrical core of resilient material having a passageway therethrough;
- an inner electrode disposed adjacent to the outer surface of said core;
- a first piezoelectric band disposed about said core having the inner surface thereof adjacent said inner electrode;
- a second piezoelectric band disposed about said core having the inner surface thereof adjacent said inner electrode;
- a third piezoelectric band disposed about said core having the inner surface thereof adjacent said inner electrode;
- an outer electrode associated with each of said first, second and third piezoelectric bands and disposed adjacent the outer surfaces thereof;
- said second piezoelectric band disposed between said first and third piezoelectric bands;
- means for selectively activating said first, second and third piezoelectric bands to contract and expand to provide a peristaltic pumping motion of the passageway through said resilient core;
- and
- means for sensing the piezoelectric effect of internal forces within the passageway of said core on said second piezoelectric band.
Dependencies are inferred from the claim text.