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US 12,120,959 B2Granted
Stacked piezoelectric energy harvester
AssigneesUniversity of Kansas, Evoke Medical, LLC
InventorsElizabeth Annamaria Friis, Ember Krech, Eileen Cadel, Bonnie Reinsch, Leighton Lapierre
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Abstract
The present application relates to stacked piezoelectric energy harvesters that include compliant layers between piezoelectric layers. The energy harvesters are useful in various structures and devices, including tissue-stimulating implants, such as spinal fusion implants. The present application also relates to methods of increasing the power output of a piezoelectric energy harvester through the inclusion of compliant layers.
Claims20
A stacked piezoelectric energy harvester, comprising:
- a. a first piezoelectric element layer;
- b. a first compliant layer positioned adjacent the first piezoelectric element layer;
- and
- c. a second piezoelectric element layer positioned adjacent the first compliant layer,
- wherein a ratio of a volume of the first piezoelectric element layer and/or a volume of the second piezoelectric element layer, to a volume of the first compliant layer is between about 1:8 volume piezoelectric:volume compliant to about 8:1 volume piezoelectric:volume compliant, or
- wherein a ratio of a thickness of the first piezoelectric element layer and/or a thickness of the second piezoelectric element layer, to a thickness of the first compliant layer is between about 1:8 thickness piezoelectric:thickness compliant to about 8:1 thickness piezoelectric:thickness compliant;
- and
- wherein the first piezoelectric element layer is poled in a radial direction and the second piezoelectric element layer is poled in a through-thickness direction;
- and, wherein the stacked energy harvester is configured to withstand a minimum load of at least 500 N.
6 more elements
A stacked piezoelectric energy harvester, comprising:
- alternating layers of:
- N compliant layers;
- and
- N−1 piezoelectric element layers;
- wherein the compliant layers and the piezoelectric element layers are adjacent one another,
- wherein N is a whole integer between 3 and 20, and
- wherein a ratio of a volume of at least one of the piezoelectric element layers, to a volume of at least one of the compliant layers is between about 1:8 volume piezoelectric:volume compliant to about 8:1 volume piezoelectric:volume compliant, or
- wherein a ratio of a thickness of at least one of the piezoelectric element layers, to a thickness of at least one of the compliant layers is between about 1:8 thickness piezoelectric:thickness compliant to about 8:1 thickness piezoelectric:thickness compliant;
- and
- wherein the stacked piezoelectric energy harvester has a total thickness in the range of 11 mm to 17 mm.
7 more elements
Dependencies are inferred from the claim text.