Investigation on a novel bellows-type piezo-hydraulic actuator

A novel bellows-type piezo-hydraulic actuator was proposed, manufactured and tested in this study. The influence of water on the piezoelectric vibrator was analyzed and the output performance of the actuator was tested. The results show that the maximum average velocities of the big bellows-type actuator (BBA) and the small bellows-type actuator (SBA) are 17.24 $\mu \text{m}{\text{s}}^{-1}$ and 27.23 $\mu \text{m}{\text{s}}^{-1}$ at 13.9 kHz. The maximum output forces are 0.163 N and 0.044 N, respectively. The self-locking forces of BBA and SBA are 0.059 N and 0.009 N. The characteristics of the actuator are simple structure, large displacement, and self-locking when power is off. (technical note)