Biomimetic Micro Underwater Vehicle with Oscillating Fin Propulsion: System Design and Force Measurement

TLDR

Boxfish locomotion has been studied biologically, yet few micro‑underwater vehicles replicate its mechanics. The study aims to design, build, and test a centimeter‑scale boxfish‑inspired microrobot capable of sustained autonomous swimming for applications such as marine sensing and underwater inspections. The vehicle is an electromechanical system with a rigid body, oscillating tail fin, and independently steered side fins, where PZT bimorph actuators drive four‑bar mechanisms to amplify fin motion, and the design is fabricated and its forces measured.

Abstract

This paper presents the design, fabrication, and force measurement of a centimeter scale micro underwater vehicle mimicking a boxfish. The principles of locomotion of real boxfish have been investigated thoroughly from a biological point of view, but attempts to replicate such a device within the research community of Micro Underwater Vehicles (MUV) have been quite limited. The authors have developed a electromechanical device with rigid body propelled by a oscillating tail fin and steered by a pair of independent side fins. The oscilating motions of the fins are independently controlled by PZT bimorph actuators driving four-bar mechanisms for motion amplification. The goal is to build a centimeter-length microrobotic fish capable of sustained autonomous swimming, which can then be used in marine micro-organism sensing, underwater ship wreck explorations, in-pipe inspections, and in forming underwater sensor networks. In this paper, we present the system concept design, fabrication and preliminary experimental measurements.