Cytotoxicity and degradation behavior of potassium sodium niobate piezoelectric ceramics

In the present study, two lead-free piezoelectric ceramics, potassium sodium niobate (K0.5Na0.5NbO3, KNN) and lithium-doped potassium sodium niobate (Li0.06K0.47Na0.47NbO3, LKNN), were prepared by a solid-state reaction process. The cytotoxicity evaluation indicated that the cytotoxicity of KNN is low. However, a strength decrease was noted after soaking in saline solution for 7 days. The addition of 6 mol% Li into the KNN improves its density; the strength and piezoelectric coefficient are enhanced consequently. Nevertheless, the cytotoxicity of LKNN is slightly higher than that of KNN. The higher cytotoxicity is related to the release of Li ions. The release of Li ion also induces the degradation of piezoelectric performance.