To evaluate these functional properties, the piezoelectric performance of PLLA films was systematically characterized. This characterization provides essential insights into how processing influences the films' electrical response and their potential as strain-sensing materials in biomedical applications such as aortic annuloplasty. The piezoelectric performance of PLLA films was evaluated through a series of mechanical and electrical tests, revealing the significant influence of molecular alignment, crystallinity, and phase transitions on their functional properties. These tests, including strain, tapping, bending while force-and frequency sweeping are illustrated in Figure . In our previous work , we established that mechanical stretching and thermal annealing significantly enhance the crystallinity and molecular alignment of PLLA films. Crystallinity increased from 36.12% in unprocessed films to 47.82%, 52.02%, and 58.45% for films strained to 50%, 75%, and 100%, respectively . These values were corroborated using Terahertz Time-Domain Spectroscopy (THz-TDS), Wide-angle X-ray scattering (WAXS), X-ray Diffraction (XRD), and Differential scanning calorimetry (DSC). This enhancement resulted in the transition from the α-phase to the β-phase, where molecular dipoles align along the polymer chain backbone, increasing the net dipole moment and improving piezoelectric activity. The molecular changes induced by processing provide a critical link between structural transformations and enhanced piezoelectric activity. This analysis forms the foundation for understanding the relationship between processing conditions and piezoelectric performance across different application scenarios .