Abstract: A novel bionic piezoelectric actuator based on the walrus motion to achieve high performance on large working stroke 
for micro/nano positioning systems is fi rst proposed in this study. The structure of the proposed walrus type piezoelectric 
actuator is described, and its motion principle is presented in details. An experimental system is set up to verify its feasibility and explore its working performances. Experimental results indicate that the proposed walrus type piezoelectric actuator could realize large working stroke with only one driving unit and one coupled clamping unit; the maximum stepping 
displacement is Δ L max = 19.5 μm in the case that the frequency f = 1 Hz and the voltage U = 120 V; the maximum speed 
V max = 2275.2 μm · s ?1 when the frequency f = 900 Hz and the voltage U = 120 V; the maximum vertical load m max = 350 g 
while the voltage U = 120 V and the frequency f = 1 Hz. This study shows the feasibility of mimicking the bionic motion 
of the real walrus animal to the design of piezoelectric actuators, which is hopeful for the real application of micro/nano 
positioning systems to achieve large working stroke and high performance.

Key words: Piezoelectric actuator, Bionic actuator, Walrus motion, Flexure mechanism