The development of biodegradable piezoelectric materials is critical for advancing eco-friendly sensors, transient electronics, and biomedical implants. Among biodegradable polymers, polylactide (PLA) exhibits intrinsic piezoelectricity, with highly dependent performance on its microstructural morphology. In this study, we examine how stereocomplex crystal (SC) formation, macromolecular orientation, and nanoparticle incorporation affect the piezoelectric response of stereocomplexed PLA (SPLA) systems. SPLA films and their nanocomposites filled with reduced graphene oxide (rGO, 0.25 wt.%) and barium titanate (BT, 10 wt.%) were processed under controlled orientation and thermal annealing conditions, where both promoted SC formation while reducing homocrystal content. Microstructural and electromechanical characterization revealed that SC-dominant systems exhibit minimal shear-mode piezoelectric output (1 mV), due to dipole cancellation between enantiomeric chains and the limited orientation. Notably, BT endowed the amorphous system with normal-mode ( d 33 ) piezoelectricity (6.2 pC/N), attributed to its intrinsic ferroelectric character. These results demonstrate that while nanofillers can influence crystallization pathways and enhance thermomechanical performance, the crystalline structure and macromolecular alignment are the dominant factors governing piezoelectric behavior. This study provides mechanistic insight into the suppression of shear piezoelectricity by stereocomplexation and offers practical strategies for designing functional, biodegradable composites with tailored electromechanical response. • Nanofillers promote stereocomplexation but hinder efficient piezo response • Barium titanate enables ( d 33 ) piezoelectricity in stereocomplex PLA matrices • Crystallinity and chain orientation dominate electromechanical behavior • Crystal phase, orientation and nanofillers collectively tune piezoelectricity • Stereocomplex crystals strongly suppress shear-mode piezoelectricity in PLA
Raef et al. (Wed,) studied this question.