KINETIC PIEZOELECTRIC CAPACITOR WITH CO-PLANAR PATTERNED ELECTRODES
A kinetic piezoelectric device is designed with: A) piezoelectric capacitor that has: 1) a substrate; 2) a first dry piezoelectric layer (first dry PL) comprising a piezoelectric material and having first and second opposing surfaces; and 3) a first pair of non-electrically-connected co-planar patterned electrodes that are arranged contiguously with at least one of the first and second opposing surfaces of the first dry PL. At least one of the first pair of non-electrically-connected co-planar patterned electrodes consists essentially of: (a) an electrically-conductive material; and (b) particles having a Young's modulus that is different from the Young's modulus of the (a) electrically-conductive material by at least 10%. The device also has B) signal processing electronics in electrical communication with the piezoelectric capacitor; and C) a means for transmitting all or a portion of an applied force directly to the first dry PL.
1 . A kinetic piezoelectric device, comprising:
A) piezoelectric capacitor comprising:
1) a substrate;
2) a first dry piezoelectric layer (first dry PL) comprising a piezoelectric material and having first and second opposing surfaces; and
3) a first pair of non-electrically-connected co-planar patterned electrodes that are arranged contiguously with at least one of the first and second opposing surfaces of the first dry PL, at least one of the first pair of non-electrically-connected co-planar patterned electrodes consisting essentially of:
(a) an electrically-conductive material; and
(b) particles distributed within the (a) electrically-conductive material, the (b) particles having a Young's modulus that is different from the Young's modulus of the (a) electrically-conductive material by at least 10%, and which (b) particles have a d50 of at least 500 nm and up to and including 500 μm and a polydispersity coefficient that is less than or equal to 3;
provided that:
the weight ratio of the (b) particles to the (a) electrically-conductive material is at least 0.01:1 and up to and including 10:1, and
when each of the first pair of non-electrically-connected co-planar patterned electrodes is arranged adjacent to an insulating substrate, it exhibits a resistivity of less than 10,000 ohms-cm;
B) signal processing electronics in electrical communication with the piezoelectric capacitor;
C) a means for transmitting all or a portion of an applied force directly to the first dry PL; and optionally
D) a proof mass that is contiguous with at least one external surface of the piezoelectric capacitor, and
optionally, each of the pair of non-electrically-connected co-planar patterned electrodes further includes (c) a binder material that is non-electrically-conductive and has a weight average molecular weight of at least 5,000.
2 . The kinetic piezoelectric device of claim 1 , wherein the (b) particles are composed of one or more polymeric materials.
3 . The kinetic piezoelectric device of claim 1 , wherein the (b) particles are composed of one or more inorganic materials.
4 . The kinetic piezoelectric device of claim 1 , wherein the (c) binder material is present in each of the first pair of non-electrically-connected co-planar electrodes, and the (c) binder material comprises one or more polyurethanes, acrylate polymers, polyvinyl acetals, or polyacrylate precursors to an acrylate polymer.
5 . The kinetic piezoelectric device of claim 1 , wherein the (c) binder material is present in each of the first pair of non-electrically-connected co-planar patterned electrodes in an amount of at least 0.1 weight % and up to and including 10 weight %, based on the total weight of each of the first pair of non-electrically-connected co-planar patterned electrodes.
6 . The kinetic piezoelectric device of claim 1 , wherein the (b) particles have a polydispersity coefficient that is less than or equal to 1.5.
7 . The kinetic piezoelectric device of claim 1 , wherein the (b) particles have a polydispersity coefficient that is less than or equal to 1.25.
8 . The kinetic piezoelectric device of claim 1 , wherein the first dry PL comprises beta phase polyvinylidene fluoride.
9 . The kinetic piezoelectric device of claim 1 , wherein the first dry PL comprises a single crystalline or polycrystalline ceramic.
10 . The kinetic piezoelectric device of claim 1 , wherein the (a) electrically-conductive material consists essentially of electrically-conductive silver nanoparticles.
11 . The kinetic piezoelectric device of claim 1 , further comprising a second dry piezoelectric layer (second dry PL) comprising a piezoelectric material, and which is arranged contiguously with the first pair of the non-electrically-connected co-planar patterned electrodes.
12 . The kinetic piezoelectric device of claim 1 that is in mechanical communication with a capacitive touch sensor.
13 . The kinetic piezoelectric device of claim 12 that is optically transparent, and wherein the capacitive touch sensor is also optically transparent.
14 . The kinetic piezoelectric device of claim 1 that is in mechanical communication with a resistive touch sensor.
15 . The kinetic piezoelectric device of claim 14 that is optically transparent, and wherein the resistive touch sensor is also optically transparent.