3D printing piezoelectric materials: Innovations, challenges, and future perspectives

Additive manufacturing (AM) is becoming an important route for creating piezoelectric materials and devices with application-driven geometries, spatially programmed functionality, and compatibility with flexible or wearable platforms. Recent progress has extended AM from simple polymer sensors to ceramic, polymer, and ceramic–polymer composite systems based on jetting, liquid resin–based printing (SLA, DLP, CLIP), extrusion or direct ink writing (DIW), powder-based processes, and emerging multi-material platforms. A central viewpoint of this review is that the electromechanical performance of 3D printed piezoelectrics depends on both the intrinsic material system (such as PZT, BTO, KNN, PVDF and PVDF-TrFE) and the way AM process parameters shape the microstructure through ink or feedstock formulation, printable feature size, curing or sintering depth, layer adhesion, and poling conditions. By organising the literature along this process–structure–property chain, different AM process can be compared on the same basis. Liquid resin–based and DIW methods at present provide the most practical balance between tens-of-micrometres resolution, shape fidelity, and compatibility with ceramic-filled or PVDF-based inks. Jetting and aerosol-jet printing are well suited to patterned thin active layers but remain highly sensitive to ink formulation. Powder-based processes still need better densification control to reach high d 33 lead-free ceramics. AM-oriented structural designs, including multilayer stacks, porosity-graded or multiphase lattices, and compliant substrates, can improve sensitivity, durability, and energy harvesting efficiency by matching mechanical impedance and promoting dipole alignment. Remaining challenges include printable high solid loading lead-free systems, stable dispersion and interfacial adhesion at low temperatures, predictive models that link print paths to poling response, and the absence of standardized benchmarking across AM platforms. The integration of data-driven optimisation and in situ monitoring with this AM process is identified as an effective way to shorten the ink-to-device iteration cycle and to deliver reproducible, application-specific 3D printed piezoelectric devices.