Harnessing Piezoelectric poly-L-lactic acid (PLLA) for Enhanced Sensing for Aortic Annuloplasty

Advancements in biomedical technologies increasingly demand biocompatible and biodegradable materials capable of integrating with the body for real-time monitoring of physiological processes. Aortic annuloplasty, a procedure to stabilize the aortic root and restore valve function in cases of regurgitation and root dilation, highlights the need for such innovations. Current methods rely on postoperative imaging, which challenges the mapping of the dynamic forces acting on the aortic root and annuloplasty ring during the cardiac cycle. To address this, we assessed the piezoelectric performance of poly-L-lactic acid (PLLA) films, fabricated using solvent casting and processed using uniaxial stretching and thermal annealing, through tapping, straining, and force- and vibration-sweep tests. These tests were conducted to characterize the electrical response of PLLA films under varying mechanical stimuli and evaluate their potential for biomedical sensing. We develop a simple prototype ring-like device to simulate real-world conditions to ascertain its suitability for integration into implantable sensors for continuous, real-time monitoring using a novel in vitro setup for biosignal monitoring of aortic annuloplasty. The device demonstrated stable and periodic voltage outputs correlated with applied pressures, ranging from -0.5 to 0.5 V at 92/51 mmHg to -1.1 to 1.3 V at 164/114 mmHg. These results establish the feasibility of PLLA-based sensors for real-time biomechanical feedback during and after cardiovascular surgeries, paving the way for next-generation monitoring technologies that enhance patient outcomes.