Surface characteristics of 3D-printed PLA/BTO piezo-polymer composite

Abstract

3D printing has emerged as a transformative technology for fabricating multiphase composite materials with tailored properties for advanced industrial applications. However, the influence of functional particle reinforcement on the surface morphology of printed bioplastics remains underexplored. This study addresses the research question: How does the incorporation of piezoelectric barium titanate (BaTiO<inf>3</inf>, BTO) particles affect the surface characteristics of 3D-printed poly-lactic acid (PLA) composites? To investigate this, a novel bioplastic composite filament was developed by extruding PLA with BTO particles, and composite specimens (PLBT) were fabricated using a 3D printing method-fused filament fabrication (FFF). A comprehensive surface characterization was performed using 3D non-contact profilometry, analyzing parameters including line and areal surface roughness, furrow formation, isotropy, peak count histograms, polar angle circular mean, mean resultant length (MRL), and Bearing Area Curve (BAC). Comparative analysis between pure PLA and PLBT samples, as well as between their top and bottom printed surfaces, revealed that the inclusion of BTO particles significantly altered the deposition behavior, resulting in increased surface roughness and distinct topographical features. Specifically, average surface roughness values increased from 8.2 µm in pure PLA to 15.8 µm in PLBT composites. The top surfaces of PLBT samples exhibited smoother textures with smaller peaks and valleys, which are advantageous for wear-sensitive applications. These findings contribute to the limited body of knowledge on the surface behavior of 3D-printed functional composites and highlight the critical role of particle reinforcement in tuning surface performance for application-specific demands. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.