ICAT Research Activities
Reliability of Actuators
The health self-monitoring system has been intensively investigated. Acoustic emission monitoring and surface potential measurement with an enbedded float electrode are good candidates for monitoring media. A strain gauge type internal electrode was trially embedded in a multilayer actuator. The resistance measurement detected the aging process of the actuator as well as a sudden failure.
Loss mechanisms in piezoelectrics have been intensively investigated. Based on this knowledge, high power electromechanical characteristics in various PZT and relaxor ferroelectric based ceramics have been exploited, and a material with the highest vibration-level v0 = 1 m/s has been developed in the PZT- Pb(Mn1/3Sb2/3)O3 system additionally doped with rare-earth (Ce, Yb, Eu). Photo 5 shows a significant result for Yb-doped PZT-PMS.
Photo 5: Yb-doped PZT-PMS piezo-ceramic exhibits
the maximum vibration velocity more than 1 m/s, which
is more than 3 times larger than the commercially
available high power piezoelectrics. This stands for more
than 10 times higher mechanical energy in the unit
volume of the ceramic.