title: A biomimetic robotic jellyfish (Robojelly) actuated by shape memory alloy composite actuators.
abstract: An analysis is conducted on the design, fabrication and performance of an underwater vehicle mimicking the propulsion mechanism and physical appearance of a medusa (jellyfish). The robotic jellyfish called Robojelly mimics the morphology and kinematics of the Aurelia aurita species. Robojelly actuates using bio-inspired shape memory alloy composite actuators. A systematic fabrication technique was developed to replicate the essential structural features of A. aurita. Robojelly's body was fabricated from RTV silicone having a total mass of 242 g and bell diameter of 164 mm. Robojelly was able to generate enough thrust in static water conditions to propel itself and achieve a proficiency of 0.19 s(-1) while the A. aurita achieves a proficiency of around 0.25 s(-1). A thrust analysis based on empirical measurements for a natural jellyfish was used to compare the performance of the different robotic configurations. The configuration with best performance was a Robojelly with segmented bell and a passive flap structure. Robojelly was found to consume an average power on the order of 17 W with the actuators not having fully reached a thermal steady state.
authors.affiliation: Center for Intelligent Material Systems and Structures (CIMSS), Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Villanueva
authors.forename: Colin
authors.initials: C
authors.lastname: Smith
authors.forename: Shashank
authors.initials: S
authors.lastname: Priya
mesh_terms: D000497:Alloys / Q000737:chemistry*; D000818:Animals; D040761:Biomimetic Materials; D003198:Computer Simulation; D017076:Computer-Aided Design; D055119:Elastic Modulus; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008954:Models, Biological; D012371:Robotics / Q000295:instrumentation*; D037401:Scyphozoa / Q000502:physiology*; D012767:Ships; D013550:Swimming / Q000502:physiology*
chemical_list: D000497:Alloys