Utilizing multilayer lithium niobate elements for ultrasonic actuators

Ultrasonic actuators are used in a wide field of applications: ultrasonic welding, turning or milling supported by ultrasound vibrations or ultrasonic motors. Piezoelectric ultrasonic actuators typically work with PZT (lead zirconate titanate) ceramics. Recently, alternative materials become more and more interesting for their use in ultrasonic actuators, due to the upcoming restrictions on using lead in new products. This study investigates the capabilities of an alternative material: LiNbO3 (lithium niobate). The two major advantages of LiNbO3 are that it is a lead free material and the high Curie temperature of 1210 °C. The work is structured in two parts: First, a new way for the assembling of LiNbO3 multilayer stacks is proposed. Second, the proposed principal transducer is setup and characterized. The maximum gained vibration amplitude was 3.5 μmRMS at the resonance-frequency of 23.5 kHz.