Abstract
In this study, we developed a new MgSiO_3 piezoelectric mixed crystal by using first-principles DFT calclations. Recently, Bio-MEMS device is developing for health monitoring system and drug delivery system. Piezoelectric materials are required biocompatibility and high piezoelectricity for actuators and sensors in the devise. MgSiO_3 with perovskite-type oxide ABO_3 is biocompatible piezoelectric materials. However piezoelectricity of MgSiO_3 is lower than that of conventional piezoelectric material. In this study, we enhanced piezoelectric property of MgSiO_3. First, we designed a mixed crystal by biocompatible element set to A or B sites of MgSiO_3 such as (Mg_<1-x>,A_x)SiO_3 and Mg(Si_<1-x>,B_x)O_3 by using first-principles DFT calculations. As a result, Mg(Si_<1/2>, Ti_<1/2>)O_3 indicated highest piezoelectric property and a possibility of a new biocompatible piezoelectric material. Next, we tried to generate Mg(Si_<1/2>, Ti_<1/2>)O_3 piezoelectric thin film by using a reactive RF magnetron sputtering. Doping Ti to MgSiO_3 was realized by changing the sputtering target putting some Ti pellets on MgO-SiO_2 sintered body target. Composition elements ratio was measured by using EDX. As a result, we succeeded the development of Zn doped MgSiO_3. And we measured piezoelectricity by using FCE. Finally, we found a new highly piezoelectric mixed crystal Mg(Si_<1/2>, Ti_<1/2>)O_3
