Session: 03-02-02 Bio-Inspired and Biomedical Fluid Mechanics

Paper Number: 87961

87961 - Experimental Investigation of Hybrid Propulsion Mechanism for Robotic Fish 

Advances in bio-robotics research and smart materials have enabled the development of bio-inspired underwater vehicles. These vehicles can serve for several engineering applications including marine environment exploration, search and rescue, military surveillance, and border patrol. In this work, we investigate the performance of a hybrid propulsion mechanism for a robotic fish based on the combined bending and flapping motions of a flexible tail with a bio-inspired caudal fin extension. The tail consists of an Aluminum substrate attached to a pair of macro-fiber composite (MFC) piezoelectric laminates and subject to flapping motion actuated by a servomotor. A testing platform, equipped with a distance laser sensor, is developed to measure the produced tail deformation over a range of actuation frequencies and amplitudes of lateral oscillations. The objective is to verify the biomimicry of the system and identify the optimal actuation that maximizes the thrust generation of the propulsive tail. Frequency response curves are generated and verified against a model of underwater beam dynamics. The experimental component of the present work includes also the development of a robotic fish prototype that encompasses a main 3d-printed body designed as a streamlined waterproof enclosure of the electronics including a microcontroller, a Raspberry Pi camera module, and a high-voltage amplifier along with a servomotor actuating the bio-inspired tail. The mass distribution of the electronic components is adjusted to ensure the buoyancy of the robotic fish in water. Free-swimming tests of the robot are successfully conducted to demonstrate the performance of the hybrid propulsion mechanism in terms of the forward swimming speed and its maneuverability.  

Presenting Author: Mehdi Ghommem American University of Sharjah