Recently, a research team led by Professor Li Bing and Professor Li Yao from the School of Robotics and Advanced Manufacturing at the Shenzhen Campus of Harbin Institute of Technology (HIT) has made significant strides in the field of micro and miniature robots. They have introduced a novel design method for a legless amphibious robot that harnesses inertial force for propulsion. This innovative approach allows the robot to perform a variety of multi-modal motions, including terrestrial crawling, continuous jumping, and precise steering and swimming at the centimeter scale, thereby offering a fresh perspective on the design of micro amphibious robots.

The research team embraced a "legless" integrated packaging design, completely enclosing the actuators and control components within a rigid shell. By leveraging internal inertial sources to generate momentum and interact with the external environment, the team effectively circumvented issues related to jamming, wear, and failure commonly associated with exposed moving parts.

Central to the robot's design is a variable-output magnetically neutral voice coil motor (VCM), which serves as the core inertial drive unit. By adjusting the driving voltage and commutation timing, the system achieves a unified platform capable of explosive jumping and high-frequency vibration propulsion. The resulting legless robot weighs a mere 24 grams, can traverse sandy terrain at a speed of approximately 1.4 times its body length per second, perform continuous jumps, carry loads exceeding 40 times its own weight, and exhibits exceptional impact resistance and terrain adaptability.

Drawing inspiration from the passive response mechanism of biological valves, the team incorporated an asymmetrically arranged array of flexible micro-undulatory fins into the robot's design for aquatic locomotion. By modulating the frequency to create thrust differentials, they developed an "Inertia-Driven Multi-Directional Propulsion" (IDMP) mechanism. Experiments demonstrate that the robot can seamlessly transition between straight movement and left/right steering by simply altering the driving frequency, achieving agile underwater motion with a minimum turning radius of just 5.6 millimeters.

This achievement systematically elucidates the multi-modal regulation mechanism of inertial drive in amphibious robots, providing a compact and reliable technical solution for applications such as miniaturized underwater exploration, disaster search and rescue operations, and inspections in complex environments.

The relevant research findings have been published in the esteemed international journal Science Advances under the title "Inertia-driven amphibious robot with asymmetric microundulatory fin arrays." The Shenzhen Campus of HIT served as the primary institution responsible for the research, with the Chinese University of Hong Kong acting as a collaborating partner.