Octopus-crawling-inspired highly agile miniature piezoelectric robot with strong load-bearing capacity

Abstract

Miniaturization, rapid mobility, load-bearing capacity, agility, and adaptability are key indicators for evaluating robots, as well as conflicting factors in the design process. Relying on conventional configuration designs to integrate these features into a single robot is challenging. Inspired by octopus crawling, we report a highly agile miniature continuous-elastomer piezoelectric robot (CEPR). Starting from the comparable modal vibration characteristics of ring-shaped structures and extracting their dominant configurations, the robotic square-circular ring structure is created in a module splicing method. The CEPR is easier to miniaturize and fabricate, measuring 28.5 × 28.5 × 7.2 mm³ and weighing 4.3 g. Its notable advantage is high agility, enabling three-degree-of-freedom movement without angle adjustment. Moreover, the CEPR possesses enhanced motion performance with linear and rotational speeds reaching 14.3 and 4.01 body lengths per second (BL/s), respectively. Sub-micron and sub-milliradian positioning accuracies are achievable, and the load-to-weight ratio of 47.84 exhibits its strong load-bearing capacity. Furthermore, the CEPR demonstrates its multitasking ability in six environmental scenarios and excels in fault inspection tasks on circuit boards. With its miniature design, exceptional mobility, and impressive load-bearing capacity, our robot demonstrates the potential to carry sensors for environmental detection in confined areas, making it ideal for space-constrained inspection duties of precision mechanical components. Overall, this study presents a unique design idea for meeting the diverse performance requirements of miniature robots.