Piezoelectric composite, ink and ink cartridge for 3D printing, bifunctional material comprising the piezoelectric composite, manufacture and uses thereof

A method of manufacture of a piezoelectric solvent-cast 3D printed material comprising a piezoelectric composite shaped into a 3D shape,

• wherein the piezoelectric composite comprises a piezoelectric polymer and particles of a filler dispersed in the polymer, wherein the filler is in micro or nanoparticle form, and wherein the filler is present in a filler:polymer weight ratio between about 1:99 and about 95:5,
• the method comprising:
• i. manufacturing the piezoelectric composite by:
• a) providing the piezoelectric polymer and particles of the filler,
• b) sonicating said filler and polymer together in the presence of a solvent, followed by mixing by ball milling, thereby forming a suspension of the filler particles in a solution of the polymer, and
• c) drying the suspension until the solvent is removed,
• ii. manufacturing a piezoelectric ink for 3D printing, wherein the ink comprises a volatile solvent, particles of a filler, and the piezoelectric composite mixed with the volatile solvent, such that the polymer is dissolved in the solvent thus forming a polymer solution and the particles of a filler are dispersed in the polymer solution, and wherein the piezoelectric ink comprises between about 0.1 and about 0.4 g of the piezoelectric composite per mL of piezoelectric ink, by:
• d) providing the volatile solvent and the particles of the filler, and
• e) sonicating the piezoelectric composite with the volatile solvent to form a suspension of the filler in a solution of the polymer, and
• iii. manufacturing said 3D printed material by:
• f) feeding the piezoelectric ink to a nozzle of a 3D printer,
• g) extruding the ink through the nozzle into a pattern;
• and
• h) allowing evaporation of the solvent, thereby providing the piezoelectric 3D printed material,
• wherein at step g), a conductive ink is extruded through a same or different nozzle of the 3D printer to form a bifunctional material comprising the piezoelectric composite with one or more conductive electrodes adjacent to the piezoelectric composite, and
• wherein the conductive ink and the piezoelectric ink have similar viscosities and are extruded simultaneously from a same nozzle of the 3D printer and the feeding step f) comprises
• feeding one side of the nozzle with one of the inks and the other side with the other
• ink, or
• feeding opposing sides of the nozzle with the conductive ink and the middle of the nozzle with the piezoelectric ink.