Polymer foam-based piezoelectric materials and method of manufacture

Patent metadata

Field	Value
Publication number	US-2016190431-A1
Application number	US-201514827596-A
Country	US
Kind code	A1
Filing date	Aug 17, 2015
Priority date	Feb 15, 2013
Publication date	Jun 30, 2016
Grant date	—

Abstract

Thermally stable piezoelectric polymer foams (ferroelectrets) with high piezoelectric activity for sensing and actuation. The invention further includes a method of fabricating such foams in an environmentally friendly manner.

First claim

What is claimed is:

1 . A method for producing a multilayer polymer ferroelectret, comprising:
fabricating a plurality of patterned polymer layers, each patterned layer comprising a plurality of cavities separated by supporting structures; fabricating a metallized polymer top layer and a metallized polymer bottom layer; arranging the patterned layers and the metallized top and bottom layers such that at least one of the patterned layers is positioned between the top and bottom metallized layers to form an assembly; coupling the layers of the assembly using a carbon dioxide bonding process to form a bonded assembly; and electrically charging the bonded assembly by subjecting the assembly to an energy source.

2 . The method of claim 1 , further comprising a first patterned polymer layer and a second patterned polymer layer.

3 . The method of claim 2 , wherein the cavities of the first patterned layer are horizontally offset from the cavities of the second patterned layer when the first and second patterned layers are arranged in the assembly.

4 . The method of claim 3 , wherein an amount of the offset is approximately equal to half of a width of the cavities.

5 . The method of claim 1 , wherein the polymer is selected from cyclo-olefin copolymer, cyclic-olefin polymer, polypropylene, polyethylene naphthalene, polyethylene terephthalate, fluorinated ethylene propylene, polytetrafluoroethylene, polyethylene, polyetherimide, and mixtures thereof.

6 . The method of claim 1 , wherein the polymer is a polymer foam.

7 . The method of claim 1 , wherein the energy source is a corona discharge or contact charge.

8 . The method of claim 1 , wherein the energy source is an electric field or current.

9 . The method of claim 1 , wherein the carbon dioxide bonding process dissolves carbon dioxide into the polymer layers.

10 . A method for producing a multilayer polymer ferroelectret, comprising:
fabricating a first patterned polymer layer and a second patterned polymer layer, each patterned layer comprising a plurality of cavities separated by support structures; fabricating a metallized polymer top layer and a metallized polymer bottom layer; fabricating a non-metallized central polymer layer; arranging the layers in the order: metallized top layer, first patterned layer, central layer, second patterned layer, and metallized bottom layer to form an assembly; coupling the layers of the assembly using a carbon dioxide bonding process to form a bonded assembly; and electrically charging the bonded assembly by subjecting the assembly to an energy source.

11 . The method of claim 10 , wherein the cavities of the first patterned layer are horizontally offset from the cavities of the second patterned layer when the first and second patterned layers are arranged in the assembly.

12 . The method of claim 11 , wherein an amount of the offset is approximately equal to half of a width of the cavities.

13 . The method of claim 10 , wherein the polymer is selected from cyclo-olefin copolymer, cyclic-olefin polymer, polypropylene, polyethylene naphthalene, polyethylene terephthalate, fluorinated ethylene propylene, polytetrafluoroethylene, polyethylene, polyetherimide, and mixtures thereof.

14 . The method of claim 10 , wherein the polymer is a polymer foam.

15 . The method of claim 10 , wherein the carbon dioxide bonding process dissolves carbon dioxide into the polymer layers.

16 . A multilayer polymer ferroelectret, comprising:
a metallized polymer top layer; a first patterned polymer layer comprising a plurality of cavities separated by supporting structures; a central non-metallized polymer layer; a second patterned polymer layer comprising a plurality of cavities separated by supporting structures, the cavities of the second patterned layer positioned in a horizontal offset from the cavities of the first patterned layer; a metallized polymer bottom layer; and positive electric charges and negative electric charges positioned apart from one another across the cavities.

17 . The ferroelectret of claim 16 , wherein an amount of the offset is approximately equal to half of a width of the cavities.

18 . The ferroelectret of claim 16 , wherein the polymer is selected from cyclo-olefin copolymer, cyclic-olefin polymer, polypropylene, polyethylene naphthalene, polyethylene terephthalate, fluorinated ethylene propylene, polytetrafluoroethylene, polyethylene, polyetherimide, and mixtures thereof.

19 . The method of claim 16 , wherein the polymer is a polymer foam.

20 . The method of claim 16 , wherein the polymer layers are at least partially saturated with carbon dioxide.

Assignees

• Univ Florida State Res Found

Inventors

• Zeng Changchun
• Li Yan

Classifications

• H01L41/193 Primary

  Electricity · mapped topic

• H01L41/39

  Electricity · mapped topic

• H01L41/277

  Electricity · mapped topic

• H01L41/083

  Electricity · mapped topic

• H10N30/857 Primary

  Macromolecular compositions · CPC title