Lead‐Free Piezoelectric (K _0.5 , Na _0.5 ) NbO ₃ ‐Natural Rubber Energy Harvester for Sensors

This study aims to develop flexible, biocompatible mechanical energy harvesters for self‐powered sensor applications, utilizing lead‐free potassium sodium niobate (K 0.5 , Na 0.5 ) NbO 3 (KNN) ceramic fillers embedded in natural rubber (NR) matrix. KNN ceramic fillers are synthesized using the conventional mixed oxide method and incorporated into the NR matrix to evaluate the effect of varying filler concentrations on the piezoelectric, dielectric, and mechanical properties of the composite. The findings suggest that as the KNN filler content increases, the electrical properties, including piezoelectric and dielectric performance, improve, whereas the mechanical properties, such as tensile strength and flexibility, decrease. This work offers a sustainable, lead‐free alternative for energy harvesting systems, with potential applications in flexible electronics, wearable devices, and biomedical sensors.