Direct micro-mechanical measurements of the material properties and motility of \textit{C. elegans}

The model organism {\it C. elegans}, a millimeter-sized nematode, provides an excellent biophysical system for both static and dynamic mechanical studies. The undulatory motion exhibited by the worm as it swims or crawls through a medium is ubiquitous in nature at scales from microns to meters, and has been the focus of intense research. However, for a successful description of this form of locomotion, a better knowledge of the material properties as well as the worm's output forces is needed. Here we present a new experimental assay, with which the material properties and dynamics of {\it C. elegans} can be directly probed. In this technique, we use the deflection of a very flexible micropipette to measure the flexural rigidity of {\it C. elegans} at all stages of its life cycle, as well as along the body of the adult worm. By modelling the worm as a viscoelastic material, we have achieved new insights into its mechanical properties. Furthermore, the forces involved during the undulatory motion of {\it C. elegans} have been studied. It is the hope that the direct experimental characterization of this model organism will provide guidance for theoretical treatments of undulatory locomotion in general.