Each object has its special frequency, through which the object can be stable and easy to oscillate. By adding external forces corresponding to the special frequency, the larger vibration can be obtained by adding smaller forces. This phenomenon is called resonance. With resonance, the blade will vibrate greatly.

      Ultrasonic cutter consists of the "transducer" which produces oscillation and "oscillator" which drives transducer. The piezoelectric element is combined in a transducer and is resonant by applying an AC voltage from the oscillator to the piezoelectric element aligned with the characteristic frequency of the transducer, including the entire vibrator of the cutting blade. The sensor has a feedback control system which can transmit the frequency or amplitude deviation information caused by cutting load to the oscillator. Feedback control system can keep the resonance state and amplitude of blade stable, and make the cutter clear and clean to cut materials.