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US 11,531,414 B2Granted
Piezoelectric films with low haze and methods of making and using
AssigneeGentex Corporation
InventorsWilliam L. Tonar, George A. Neuman, Mario F. Saenger Nayver, Kurtis L. Geerlings, Sue F. Franz
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Abstract
A touch-sensitive assembly and method of making includes a first electrically conductive layer disposed on a first substrate and a second electrically conductive layer disposed on a second substrate. A piezoelectric film is disposed between the first electrically conductive layer and the second electrically conductive layer. The piezoelectric film includes a plurality of aligned piezoelectric particles disposed in a polymeric matrix and is characterized by a haze value of about 5% or less.
Claims20
A touch-sensitive assembly, comprising:
- a first electrically conductive layer disposed on a first substrate;
- a second electrically conductive layer disposed on a second substrate;
- and
- a piezoelectric film disposed between the first electrically conductive layer and the second electrically conductive layer, wherein the piezoelectric film comprises a plurality of aligned piezoelectric particles disposed in a polymeric matrix, and
- wherein the piezoelectric film is characterized by a haze value of about 5% or less;
- and
- wherein the polymeric matrix further comprises:
- a filler, wherein at least one of a type and amount of the filler is selected to change an index of refraction of the polymeric matrix such that a difference in an index of refraction of the piezoelectric particles and the index of refraction of the polymeric matrix is less than about ±1, as measured for at least one wavelength in the range of from about 400 nm to about 700 nm.
5 more elements
A method of making a touch-sensitive assembly, comprising:
- providing a first electrically conductive layer disposed on a first substrate;
- providing a second electrically conductive layer disposed on a second substrate;
- providing (i) a first material selected from a polymer solution, polymer melt, reactive monomers, reactive prepolymers, and combinations thereof, and (ii) piezoelectric particles dispersed within the first material;
- applying an electric field to the first material to align the piezoelectric particles along a first axis to form a second material;
- solidifying the second material to form a piezoelectric film comprising aligned piezoelectric articles disposed within a polymeric matrix;
- and
- disposing the piezoelectric film between the first electrically conductive layer and the second electrically conductive layer,
- wherein the piezoelectric film is characterized by a haze value of about 5% or less;
- wherein the polymeric matrix comprises a silicone-based polymer resin, and atoms of a metal take the place of a portion of silicon atoms in the polymeric matrix to change a refractive index of the polymeric matrix to be closer to an index of refraction of the piezoelectric particles;
- and
- wherein a difference in the index of refraction of the piezoelectric articles and the index of refraction of the polymeric matrix is less than about 1, as measured for at least one wavelength in the range of from about 400 nm to about 700 nm.
8 more elements
A touch-sensitive assembly, comprising:
- a first electrically conductive layer disposed on a first substrate;
- a second electrically conductive layer disposed on a second substrate;
- and
- a piezoelectric film disposed between the first electrically conductive layer and the second electrically conductive layer, wherein the piezoelectric film comprises:
- a plurality of aligned piezoelectric particles disposed in a polymeric matrix, wherein the piezoelectric particles comprise a first index of refraction and the polymeric matrix comprises a second index of refraction;
- and
- at least one of (i) a coating disposed on the piezoelectric particles, wherein the coating is characterized by a third index of refraction that is intermediate between the first index of refraction and the second index of refraction and (ii) a gradient coating disposed on the piezoelectric particles, wherein the gradient coating comprises a fourth index of refraction adjacent an interface between the piezoelectric particles and the gradient coating and a fifth index of refraction adjacent an interface between the polymeric matrix and the gradient coating;
- wherein the piezoelectric film is characterized by a haze value of about 5% or less.
5 more elements
Dependencies are inferred from the claim text.