A high displacement ultrasonic actuator based on a flexural mechanical amplifier

Commonly used high displacement ultrasonic actuators are composed of a Langevin transducer and of a sectional ultrasonic concentrator working as a displacement amplifier. In this work, a novel ultrasonic actuator, which exploits a displacement amplifier vibrating in a flexural mode, is proposed. Design and analysis of the actuator have been performed by using a FEM software. Performances of the proposed actuator have been evaluated by using a classical ultrasonic actuator, based on a stepped horn concentrator, as a benchmark. Simulated results have shown that the flexural amplifier exhibits a displacement amplification about 50% higher than that of the stepped horn; furthermore, due to its capability to absorb a higher electrical power, the whole actuator has shown a maximum displacement that is twice the maximum displacement of the stepped horn actuator. Simulated results have been validated by measurements carried out on two manufactured prototypes.