Harnessing piezoelectric poly L lactic acid for enhanced sensing in 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 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 via solvent casting and processed using uniaxial stretching and thermal annealing, through tapping, straining, and force- and vibration-sweep tests. These experiments characterized the electrical response of PLLA films under varying mechanical stimuli and evaluated their potential for biomedical sensing. We developed a ring-like prototype device to simulate real-world conditions and assess its suitability for implantable sensors using an 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 findings support the feasibility of PLLA-based sensors for real-time biomechanical feedback in cardiovascular surgery.