Dynamics of Centipede Locomotion Revealed by Large-Scale Traction Force Microscopy (J. Roy Soc INTERFACE, to be published, march 2024)

<p>data and matlab code&nbsp; from paper "Dynamics of Centipede Locomotion Revealed by Large-Scale Traction Force Microscopy" &nbsp;(paper submitted to J. Roy Soc INTERFACE, to be published, march 2024)</p> <p><strong><span>Dynamics of Centipede Locomotion Revealed by Large-Scale Traction Force Microscopy</span></strong></p> <p><span>&nbsp;</span><span>J.P. Rieu</span>^{<span>1, *</span>}<span>, H. Delano&euml;-Ayari</span>^{<span>1</span>}<span>, C. Barentin</span>^{<span>1</span>}<span>, T. Nakagaki</span>^{<span>2</span>}<span> and S. Kuroda</span>^{<span>3</span>}^{<span> ,*</span>}</p> <p>^{<span>1</span>}<span> </span><span>Institut Lumi&egrave;re Mati&egrave;re, University of Lyon, Universit&eacute; Claude Bernard Lyon 1, CNRS, F-69622, Villeurbanne, France</span></p> <p>^{<span>2</span>}<span> Research Institute for Electronic Science, Hokkaido University, N20W10 Kita-ku, Sapporo Hokkaido 001-0020, Japan</span></p> <p>^{<span>3 </span>}<span>Faculty of Software and Information Technology, Aomori University, Koubata 2-3-1, Aomori, 030-0943, Japan</span></p> <p><span>* Authors for correspondence:<span>&nbsp; </span>Jean-Paul Rieu (e-mail: jean-paul.rieu@univ-lyon1.fr) and Shigeru Kuroda (shigeru-kuroda@aomori-u.ac.jp)</span></p> <p>&nbsp;</p> <p><strong><span>Abstract</span></strong></p> <p><span>We present a novel approach to traction force microscopy (TFM) for studying the locomotion of 10cm-long walking centipedes on soft substrates.</span><span> Leveraging the </span><span>remarkable</span><span> elasticity and ductility of kudzu starch gels, we utilize them as a deformable gel substrate, providing resilience against the centipedes' sharp leg tips. </span><span>Through optimizing fiducial marker size and density and fine-tuning imaging conditions, we enhance measurement accuracy. Our TFM investigation reveals traction forces along the centipede's longitudinal axis that effectively counterbalance inertial forces within the 0-10mN range, providing the first report of non-vanishing inertia forces in TFM studies. Interestingly, we observe waves of forces propagating from the head to the tail of the centipede, corresponding to its locomotion speed. Furthermore, we discover a characteristic cycle of leg clusters engaging with the substrate: forward force (friction) upon leg tip contact, backward force (traction) as the leg pulls the substrate while stationary, and subsequent forward force as the leg tip detaches to reposition itself in the anterior direction. </span><span>This work </span><span>opens perspectives for TFM applications in ethology, tribology, and robotics</span><span>.</span></p>