Porous fluid sensor
Assignee3M Innovative Properties Company
InventorsJohn A. Wheatley, William B. Kolb, Audrey A. Sherman, Mark A Roehrig, Alan R. Dombrowski, Kurt J. Halverson, Steven P. Swanson, Del R. Lawson, Cory M. Arthur
Life of this patent
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Abstract
An optical element includes a porous layer with a network of a plurality of interconnected voids. The porous layer is optically diffusive to at least one wavelength of light when the network of interconnected voids is substantially free of fluid. The porous layer of the optical element undergoes a detectable optical change upon fluid ingress into the network or egress from the network of interconnected voids.
Claims16
A fluid sensor comprising a porous layer with a network of a plurality of interconnected voids, wherein the porous layer is optically diffusive to at least one wavelength of light when the network is substantially free of fluid, and wherein the porous layer undergoes a detectable optical change upon fluid ingress into the network or egress from the network, the fluid sensor further comprising a first polymeric film on a first major surface of the porous layer.
A closure device, comprising:
- a body comprising an interior chamber;
- a fluid in the interior chamber;
- a component in the interior chamber, wherein the component comprises a fluid sensor, the fluid sensor comprising a layer of a porous material with a network of a plurality of interconnected voids;
- wherein the fluid sensor undergoes a detectable optical change based on presence of the fluid in the interior chamber;
- and
- wherein the layer of the porous material comprises a porous polymeric film, and wherein a first local volume fraction of the plurality of interconnected voids proximate a first major surface of the porous polymeric film is greater than a second local volume fraction of the plurality of interconnected voids proximate an opposed second major surface of the porous polymeric film, and wherein the porous polymeric film comprises a single layer with a thickness of greater than 2 microns.
Dependencies are inferred from the claim text.