A bio-robotic platform for integrating internal and external mechanics during muscle-powered swimming

Richards, Christopher T. and Clemente, Christofer J. (2012) A bio-robotic platform for integrating internal and external mechanics during muscle-powered swimming. Bioinspiration and Biomimetics, 7 1: 016010-1-016010-15. doi:10.1088/1748-3182/7/1/016010

Author Richards, Christopher T.
Clemente, Christofer J.
Title A bio-robotic platform for integrating internal and external mechanics during muscle-powered swimming
Journal name Bioinspiration and Biomimetics   Check publisher's open access policy
ISSN 1748-3182; 748-3190
Publication date 2012-03
Year available 2012
Sub-type Article (original research)
DOI 10.1088/1748-3182/7/1/016010
Volume 7
Issue 1
Start page 016010-1
End page 016010-15
Total pages 15
Place of publication Bristol, United Kingdom
Publisher Institute of Physics Publishing (IOP)
Collection year 2013
Language eng
Formatted abstract
To explore the interplay between muscle function and propulsor shape in swimming animals, we built a robotic foot to mimic the morphology and hind limb kinematics of Xenopus laevis frogs. Four foot shapes ranging from low aspect ratio (AR = 0.74) to high (AR = 5) were compared to test whether low-AR feet produce higher propulsive drag force resulting in faster swimming. Using feedback loops, two complementary control modes were used to rotate the foot: force was transmitted to the foot either from (1) a living plantaris longus (PL) muscle stimulated in vitro or (2) an in silico mathematical model of the PL. To mimic forward swimming, foot translation was calculated in real time from fluid force measured at the foot. Therefore, bio-robot swimming emerged from musclefluid interactions via the feedback loop. Among in vitro-robotic trials, muscle impulse ranged from 0.12 ± 0.002 to 0.18 ± 0.007 N s and swimming velocities from 0.41 ± 0.01 to 0.43 ± 0.00 m s 1, similar to in vivo values from prior studies. Trends in in silico-robotic data mirrored in vitro-robotic observations. Increasing AR caused a small (∼10%) increase in peak bio-robot swimming velocity. In contrast, muscle forcevelocity effects were strongly dependent on foot shape. Between low- and high-AR feet, muscle impulse increased ∼50%, while peak shortening velocity decreased ∼50% resulting in a ∼20% increase in net work. However, muscle-propulsion efficiency (body center of mass work/muscle work) remained independent of AR. Thus, we demonstrate how our experimental technique is useful for quantifying the complex interplay among limb morphology, muscle mechanics and hydrodynamics.
Keyword Pectoral Fin
Labriform Propulsion
Revolving Wings
Body Dynamics
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Non HERDC
School of Biological Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 9 times in Thomson Reuters Web of Science Article | Citations
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Created: Sun, 14 Apr 2013, 23:31:17 EST by Gail Walter on behalf of School of Biological Sciences