Compatibility Analysis of Piezoelectric Actuators in Supercritical Carbon Dioxide

The compatibility of a multilayer piezoelectric actuator operating in supercritical carbon dioxide was tested using a voltage-based self-sensing technique. The phase transitions of carbon dioxide to supercritical state were recorded visually. No degradation was observed in leakage current of the piezoelectric actuator after being immersed in supercritical carbon dioxide for hours. This confirmed compatibility allows further applications of supercritical carbon dioxide as the insulating medium in power equipment, like a fast mechanical switch for hybrid direct current circuit breakers in medium voltage direct current power systems.