Piezoelectric composite filaments and use thereof in additive manufacturing
Parts made by additive manufacturing are often structural in nature, rather than having functional properties conveyed by a polymer or other component. Printed parts having piezoelectric properties may be formed using a composite filament comprising a plurality of piezoelectric particles dispersed in a thermoplastic polymer. The composite filaments may be formed through melt blending and extrusion. The composite filament is compatible with fused filament fabrication and has a length and diameter compatible with fused filament fabrication, and the piezoelectric particles are substantially non-agglomerated and dispersed along the length of the composite filament. The piezoelectric particles may remain substantially non-agglomerated when dispersed in the thermoplastic polymer through melt blending. Additive manufacturing processes may comprise heating such a composite filament at or above a melting point or softening temperature thereof to form a softened composite material, and depositing the softened composite material layer by layer to form a printed part.
1 . A composite filament comprising:
a plurality of piezoelectric particles dispersed in a thermoplastic polymer;
wherein the thermoplastic polymer is non-piezoelectric and is selected from the group consisting of a polyamide, a polycaprolactone, a polystyrene, a poly(styrene-isoprene-styrene) (SIS), a poly(styrene-ethylene-butylene-styrene) (SEBS), a poly(styrene-butylene-styrene) (SBS), a high-impact polystyrene, a thermoplastic polyurethane, a poly(vinylpyrrolidine-vinylacetate), a polyester, polyethylene terephthalate, polyethylene naphthalate, a polycarbonate, a polyethersulfone, a polyoxymethylene, a polyether ether ketone, a polyetherimide, a polyethylene, a polyethylene oxide, a polyphenylene sulfide, a polypropylene, any copolymer thereof, and any combination thereof; and
wherein the composite filament is substantially free of voids, and is compatible with fused filament fabrication and has a length and diameter compatible with fused filament fabrication, and the piezoelectric particles are substantially non-agglomerated and dispersed along the length of the composite filament.
2 . The composite filament of claim 1 , wherein the piezoelectric particles are present in a sufficient amount such that the composite filament is capable of being printed as a single-layer thin film having a d 33 value, after poling, of about 1 pC/N or more at a film thickness of about 200 microns, as measured using an APC International Wide-Range d 33 meter.
3 . The composite filament of claim 1 , wherein the piezoelectric particles have an average particle size of about 10 microns or less.
4 . The composite filament of claim 1 , wherein the piezoelectric particles comprise about 10 vol. % to about 85 vol. % of the composite filament.
5 . The composite filament of claim 1 , wherein the piezoelectric particles comprise a piezoelectric material selected from the group consisting of lead zirconate titanate, doped lead zirconate titanate, barium titanate, lead titanate, lead magnesium niobate, lead magnesium niobate-lead titanate, sodium potassium niobate, calcium copper titanate, bismuth sodium titanate, gallium phosphate, quartz, tourmaline and any combination thereof.
6 . The composite filament of claim 1 , wherein the thermoplastic polymer is selected from the group consisting of a polyamide, a polycaprolactone, a poly(styrene-isoprene-styrene) (SIS), a poly(styrene-ethylene-butylene-styrene) (SEBS), a poly(styrene-butylene-styrene) (SBS), a polyester, any copolymer thereof, and any combination thereof.
7 . The composite filament of claim 1 , wherein the thermoplastic polymer is selected from the group consisting of a polyamide, a polycaprolactone, a poly(styrene-isoprene-styrene) (SIS), a poly(styrene-ethylene-butylene-styrene) (SEBS), a poly(styrene-butylene-styrene) (SBS), any copolymer thereof, and any combination thereof.
8 . A process comprising:
forming a melt comprising a thermoplastic polymer and a plurality of piezoelectric particles;
wherein the thermoplastic polymer is non-piezoelectric and is selected from the group consisting of a polyamide, a polycaprolactone, a polystyrene, a poly(styrene-isoprene-styrene) (SIS), a poly(styrene-ethylene-butylene-styrene) (SEBS), a poly(styrene-butylene-styrene) (SBS), a high-impact polystyrene, a thermoplastic polyurethane, a poly(vinylpyrrolidine-vinylacetate), a polyester, polyethylene terephthalate, polyethylene naphthalate, a polycarbonate, a polyethersulfone, a polyoxymethylene, a polyether ether ketone, a polyetherimide, a polyethylene, a polyethylene oxide, a polyphenylene sulfide, a polypropylene, any copolymer thereof, and any combination thereof;
blending the melt, optionally with stirring, to form a melt blend having the piezoelectric particles distributed therein; and
extruding the melt blend to form a composite filament comprising the plurality of piezoelectric particles dispersed in the thermoplastic polymer;
wherein the composite filament is substantially free of voids, and is compatible with fused filament fabrication and has a length and diameter compatible with fused filament fabrication, and the piezoelectric particles are substantially non-agglomerated and dispersed along the length of the composite filament; and
wherein forming, blending, and extruding occur sequentially or simultaneously.
9 . The process of claim 8 , wherein the piezoelectric particles are present in a sufficient amount such that the composite filament is capable of being printed as a single-layer thin film having a d 33 value, after poling, of about 1 pC/N or more at a single-layer film thickness of about 200 microns, as measured using an APC International Wide-Range d 33 meter.
10 . The process of claim 8 , wherein the piezoelectric particles have an average particle size of about 10 microns or less.
11 . The process of claim 8 , wherein the piezoelectric particles comprise about 10 vol. % to about 85 vol. % of the composite filament.
12 . The process of claim 8 , wherein the piezoelectric particles comprise a piezoelectric material selected from the group consisting of lead zirconate titanate, doped lead zirconate titanate, barium titanate, lead titanate, lead magnesium niobate, lead magnesium niobate-lead titanate, sodium potassium niobate, calcium copper titanate, bismuth sodium titanate, gallium phosphate, quartz, tourmaline and any combination thereof.
13 . The method of claim 8 , wherein the piezoelectric particles are processed by probe sonication before being combined with the thermoplastic polymer.
14 . A process comprising:
providing a composite filament comprising a plurality of piezoelectric particles dispersed in a thermoplastic polymer;
wherein the thermoplastic polymer is non-piezoelectric and is selected from the group consisting of a polyamide, a polycaprolactone, a polystyrene, a poly(styrene-isoprene-styrene) (SIS), a poly(styrene-ethylene-butylene-styrene) (SEBS), a poly(styrene-butylene-styrene) (SBS), a high-impact polystyrene, a thermoplastic polyurethane, a poly(vinylpyrrolidine-vinylacetate), a polyester, polyethylene terephthalate, polyethylene naphthalate, a polycarbonate, a polyethersulfone, a polyoxymethylene, a polyether ether ketone, a polyetherimide, a polyethylene, a polyethylene oxide, a polyphenylene sulfide, a polypropylene, any copolymer thereof, and any combination thereof; and
wherein the composite filament is substantially free of voids, and is compatible with fused filament fabrication and has a length and diameter compatible with fused filament fabrication, and the piezoelectric particles are substantially non-agglomerated and are dispersed along the length of the composite filament;
heating the composite filament at or above a melting point or softening temperature thereof to form a softened composite material; and
depositing the softened composite material layer by layer to form a printed part; and
wherein heating and depositing occur sequentially or simultaneously.
15 . The process of claim 14 , wherein the piezoelectric particles are present in a sufficient amount such that the composite filament is capable of being printed as a single-layer thin film having a d 33 value, after poling, of about 1 pC/N or more at a film thickness of about 200 microns, as measured using an APC International Wide-Range d 33 meter.
16 . The process of claim 14 , wherein the piezoelectric particles have an average particle size of about 10 microns or less.
17 . The process of claim 14 , wherein the piezoelectric particles comprise about 10 vol. % to about 85 vol. % of the composite filament.
18 . The process of claim 14 , wherein the piezoelectric particles comprise a piezoelectric material selected from the group consisting of lead zirconate titanate, doped lead zirconate titanate, barium titanate, lead titanate, lead magnesium niobate, lead magnesium niobate-lead titanate, sodium potassium niobate, calcium copper titanate, bismuth sodium titanate, gallium phosphate, quartz, tourmaline and any combination thereof.
19 . The process of claim 14 , further comprising:
poling at least a portion of the printed part.