Piezoelectric poly-L-lactic acid for next-generation energy harvesting and biomedical applications

Poly-L-lactic acid (PLLA) has attracted increasing attention as a piezoelectric polymer material due to its biodegradability, biocompatibility and shear piezoelectric properties, making it a promising candidate for various applications like self-powered sensors, biomedical devices and next generation flexible electronics. Herein, this work summarizes the latest research progress on the piezoelectric performance of PLLA and its composites, focusing on the strategies for improving piezoelectric properties through molecular orientation, crystallinity optimization, nanostructure construction and composite engineering. Processing techniques such as electrospinning, hot stretching, solvent casting, 3D printing, template infiltrating and melt spinning are introduced, and how they affect molecular orientation, crystal phase as well as piezoelectric output. In addition, we emphasize degradation behavior of PLLA-based piezoelectric materials, and we also discuss their applications in energy harvesting, medical health and in vivo validation. Finally, this work introduces the current challenges and future directions for the design and preparation of high-performance and environmentally friendly piezoelectric systems based on PLLA.