The influence of low-temperature sterilization procedures on piezoelectric ceramics for biomedical applications

Abstract

Piezoelectric materials are intensively investigated for usage in biomedical applications ranging from in vivo sensors and energy harvesters to implants for bone and neural cell stimulation. Besides the high requirements for reliability and low cytotoxicity, implantable materials must be sterilizable without losing their functionality. In this study, we investigate the impact of low temperature plasma sterilization and the associated cleaning routines on the piezoelectric properties of PZT, BCZT and KNN bulk ceramics. The stability of the piezoelectric response strongly depends on the material system, with BCZT ceramics showing the strongest decline in properties. Several factors were identified to contribute to this reduction of the piezoelectric coefficient, the most important being mechanical stress due to sample handling as well as chemical reactions during cleaning, disinfection and sterilization. The study highlights the importance of evaluating the impact of all influencing factors along the pre-implantation handling chain in the material selection process.