Design and evolution of a piezoelectrically actuated miniature swimming vehicle

This work details the design of a miniature swimming vehicle that propels itself through oscillations of a flexible fin mounted in the stern. The fin is driven through a mechanism that is actuated by two curved-beam bending piezoelectric actuators. An optimization routine is used to design the mechanism for rigid body guidance. The actuators are modeled statically using the Bernoulli-Euler method. Hamilton's principle is applied to the actuators and, by employing modal analysis, a dynamic actuator model is developed and compared to experimental data. The physical evolution of the swimming vehicle is discussed,, and a prototype for an onboard digital control circuit is evaluated. The latest vehicle design, which incorporates onboard digital control, is presented in terms of its design and experimentally determined performance characteristics. The current swimming vehicle prototype achieves fish-like maneuvering and an approximate velocity of 0.25 m/s.