A miniature wireless robotic swimmer actuated by a vector acoustic system

Untethered underwater robots are capable of navigating confined aquatic environments, offering significant potential for applications such as environmental monitoring, pipeline inspection and biological sample collection. However, traditional propeller propulsion systems suffer from limited maneuverability and potential safety risks in confined spaces. To address these challenges, we propose a miniature robotic swimmer (8.5 cm in diameter and 10 cm in height) actuated by a vector acoustic system. Specifically, the robot employs a piezoelectric transducer to generate high-intensity ultrasonic waves, which produce a directional jet in the fluid by acoustic radiation force. By using a miniature electromagnetic motor to adjust the alignment of the piezoelectric actuator, the system can modify the jet direction, achieving full-range propulsion without turning radius limitations. Moreover, the combined implementation of a vectorized propulsion system with a wireless control module enables superior maneuverability. Experiments show that the robot achieves a maximum linear velocity of 79.2 mm/s and can traverse a narrow gap of 1.5 times the body length under remote wireless control, demonstrating excellent maneuverability and obstacle avoidance capability.