Building biology: Using an artificial ribbon fin system to understand locomotion of a gymnotiform swimmer, Apteronotus albifrons
Disciplines
Evolution | Other Mechanical Engineering
Abstract (300 words maximum)
Over the past decade, engineers have designed Autonomous Underwater Vehicles (AUVs) inspired by the gymnotiform swimmer, the Black ghost knifefish (Apteronotus albifrons). A. albifrons is highly maneuverable due to using its elongated anal fin which is referred to as a ribbon fin. Current AUVs inspired by this propulsive system use multiple servo motor inputs which could cause reduced efficiency. While these AUVs use multiple rods and servo motors to mimic fin rays, it is still unknown if all fin rays must be active to generate thrust. In order to understand the possibility of passive wave generation and suggest a more efficient AUV design, this project developed an experimental artificial ribbon fin (ARF) system using 4 foil thicknesses (0.002, 0.003, 0.004, 0.005 mm) attached to a control arm of a single servo motor oscillating at 3 frequencies (1.09, 0.7, and 0.48 Hz). Wave measurements were extracted in 2D from high speed videos (250 fps-1) using ImageJ. The thinnest (0.002 mm) and thickest (0.005 mm) foils were expected to be less comparable to previously observed wave measurements of the live animal. An intermediate foil (0.003 mm) displayed the closest wave measurement values at the oscillating frequency of 1.09 Hz. Significant differences in most wave measurements both within the foils across frequencies and among the foils at each frequency occurred. These preliminary results will supplement future efforts to develop a more realistic robotic model to be used in further exploration of this propulsive system.
Academic department under which the project should be listed
CSM - Ecology, Evolution, and Organismal Biology
Primary Investigator (PI) Name
Chris Sanford
Building biology: Using an artificial ribbon fin system to understand locomotion of a gymnotiform swimmer, Apteronotus albifrons
Over the past decade, engineers have designed Autonomous Underwater Vehicles (AUVs) inspired by the gymnotiform swimmer, the Black ghost knifefish (Apteronotus albifrons). A. albifrons is highly maneuverable due to using its elongated anal fin which is referred to as a ribbon fin. Current AUVs inspired by this propulsive system use multiple servo motor inputs which could cause reduced efficiency. While these AUVs use multiple rods and servo motors to mimic fin rays, it is still unknown if all fin rays must be active to generate thrust. In order to understand the possibility of passive wave generation and suggest a more efficient AUV design, this project developed an experimental artificial ribbon fin (ARF) system using 4 foil thicknesses (0.002, 0.003, 0.004, 0.005 mm) attached to a control arm of a single servo motor oscillating at 3 frequencies (1.09, 0.7, and 0.48 Hz). Wave measurements were extracted in 2D from high speed videos (250 fps-1) using ImageJ. The thinnest (0.002 mm) and thickest (0.005 mm) foils were expected to be less comparable to previously observed wave measurements of the live animal. An intermediate foil (0.003 mm) displayed the closest wave measurement values at the oscillating frequency of 1.09 Hz. Significant differences in most wave measurements both within the foils across frequencies and among the foils at each frequency occurred. These preliminary results will supplement future efforts to develop a more realistic robotic model to be used in further exploration of this propulsive system.