Piezoelectric composite filaments and use thereof in additive manufacturing

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.

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.