Geometric Swimming with an Extensible Backbone

In this work, we consider the effect of curvature-coupled backbone extensibility on the efficiency of swimming systems. We consider two backbones with extensible curvature. One, in which the deformation is piecewise-constant along the body, is inspired by soft pneumatic actuators, while the other encodes a serpenoid motion in which the curvature is a sinusoidal wave traveling along the body. Maximum-efficiency gaits are identified for various levels of extensibility, and the results are compared to non-extensible systems at RMS-equivalent body-lengths.

Initial results indicate that active extensibility can provide improved locomotion performance. Serpenoid system performance suggests a limit to attainable efficiency, as that backbone contains a higher number of segments. Future work will include performing this analysis on an experimentally derived set of kinematics.