Development of a miniature quadrupedal piezoelectric robot combining fast speed and nano-resolution

Miniature piezoelectric robots exhibit superior performances and have been favored by many researchers, however, there is an intractable contradiction between nano-resolution and fast speed. Inspired by motion of quadrupeds, we proposed a miniature quadruped piezoelectric robot (MQPR), which combined quasi-static motion and resonant motion to realize nano-resolution and high speed, respectively. Two theoretical models were established to determine the parameters of the proposed piezo-leg, and they were verified by experiments. A prototype with size of 35 × 44 × 12 mm³ and weight of 21.0 g was manufactured and tested. The measured results showed that the MQPR realized multi-DOF motions with resolution of less than 8.8 nm and range of about 2 μm in quasi-static motion, and achieved a linear speed of 393.5 mm/s (11.2 BL/s) and a rotational speed of 246.5 °/s in resonant motion. Moreover, a resolution of 0.31 μm was obtained by resonant motion in pulse mode, which could achieve effective cooperation of the above two motion mechanisms. In addition, the load capacity of the MQPR was 100 g, which was about 5 times its own weight. These characteristics help the MQPR have great potential to efficiently perform precision manipulations at multiple target locations over a large area, such as detection of circuit board in large integrated circuits or wafers.