A Miniaturized T-Shaped Inchworm Piezoelectric Actuator Inspired by Stick Insect With High Speed

This article presents a miniaturized T-shaped inchworm piezoelectric actuator (PA) inspired by stick insect motion, which contributes to the reduction and speed enhancement for inchworm PA. Clamping and driving motion can be realized by the concerted actuation of two driving units, which reduces the number of piezoelectric stack actuators (PSAs) to realize the inchworm working principle. The displacement amplification characteristics of the bridge-type mechanism are employed to preliminarily reduce the PA volume. Amultiobjective design optimization method integrating a backpropagation neural network with particle swarm optimization is further proposed to minimize the actuator size to 40 × 25 × 7 mm3. Experimental results showed that the proposed inchworm PA achieved an improved maximum speed of 4547.29 μm/s under a voltage of 150 V and a frequency of 300 Hz. Furthermore, it delivered an output force of 2.3 N and exhibited stable step under a 4 kg load with no backward motion.