Decoupling Piezoelectric And Pyroelectric Effects In Anisotropic Polymer-Ceramic Lattices Produced Via Fused Filament Fabrication

This thesis investigates how multi-material fused filament fabrication (FFF) can be used to engineer lattice structures that decouple piezoelectric and pyroelectric responses within a single polymer–ceramic composite. A hybrid ABS–BaTiO3/PLA lattice—referred to as the Hybrid PIZCAL—was designed to direct mechanical strain along the Z-axis while suppressing deformation in the transverse directions. After thermal poling, the lattice exhibited a 293% increase in Z-axis voltage sensitivity compared to a monolithic ABS–BaTiO3 cube and significantly reduced off-axis electromechanical output. Finite element simulations and directional compression testing confirmed that geometric anisotropy and material zoning produce strong, axis-selective piezoelectric behavior. The second part of this work evaluates the thermal response of the composite and examines whether piezoelectric and pyroelectric effects can be separated during simultaneous loading. Pyroelectric testing under controlled heating–cooling cycles established consistent thermal transients below the BaTiO3 Curie temperature. Combined thermo–mechanical experiments—cyclic compression with infrared heating—demonstrated functional decoupling within the Hybrid PIZCAL: the Z-axis produced mixed piezo–pyro signals, while the Y-axis generated a purely pyroelectric response with no detectable mechanical contribution. These results show that additive manufacturing can intentionally control both mechanical and thermal pathways to isolate different sensing modes. The demonstrated decoupling provides a foundation for lightweight, low-cost, multifunctional sensors capable of distinguishing force and temperature in complex environments.