Ultrasonic-based material processing apparatus and control method thereof

An ultrasonic-based material processing apparatus comprising:

• an ultrasonic transfer unit configured to accommodate a processing target material;
• an ultrasonic generation unit disposed on a lateral surface of the ultrasonic transfer unit and comprising a piezoelectric element configured to generate ultrasonic waves;
• a power supply unit configured to output driving power to the ultrasonic generation unit;
• and
• a controller, wherein the controller
• controls the power supply unit so that test power is supplied from the power supply unit to the ultrasonic generation unit,
• determines a resonant frequency of the piezoelectric element based on an output of the piezoelectric element as a response to the test power,
• determines a first driving frequency and a second driving frequency based on the resonant frequency, and
• controls the power supply unit so that first driving power having the first driving frequency and second driving power having the second driving frequency are applied from the power supply unit to the ultrasonic generation unit.