Design of a manta ray inspired underwater propulsive mechanism for long range, low power operation

Ocean exploration and data gathering have become more important and desirable than ever before, but the high cost of performing such operations with ship based platforms prevents researchers from probing the oceans extensively. New autonomous underwater vehicles (AUVs) were developed in mid-1990s to overcome the prohibitive costs of ocean research and much progress has been made. However, the performance of current AUVs still leave much to be desired in terms of speed, maneuverability, and mission durations.; This study examines the design and prototype development of a propulsive mechanism based on that of a manta ray (Manta birostris ). Manta rays are pelagic creatures which have developed a very efficient swimming motion over thousands of years of evolution. The swimming motion of a manta ray is characterized by high amplitude, low frequency pectoral fin flapping which is ideal for a low power robotic system. A manta ray based underwater vehicle would propel itself silently and would be capable of very long duration missions while retaining a high degree of maneuverability.; This study resulted in the development of actuators capable of mimicking the motion of a manta ray pectoral fin. The actuators were embedded in a plastic pectoral fin form and mounted on a testing barge to analyze its performance.