Year: 2026
Type: preprint
Abstract: Fiberboids are filaments that self-propel by rolling along a surface due to a flux normal to that surface. In the last few years, fibers using several materials and driving mechanisms have been developed that are able to roll persistently. Here we show using thermally driven nylon fibers on a slightly curved glass surface, that fiberboids also come in another state, that we call ``twitching'': the fiber rolls for a short time and then switches direction, implementing on large scales a diffusion-like motion. We rationalize the occurrence of this effect and experimentally quantify this new dynamic state. We then analyze ensembles of twitching fiberboids and by confining the fibers inside a circular arena to allow them to roll on a single axis only, we implement a simple, table-top realization of a one-dimensional non-equilibrium active gas. We study experimentally active cluster formation, their non-equilibrium dynamics and we rationalize the observations by a simple lattice model. This model takes into account a Viscek-like alignment of the velocity directions of the individual particles within clusters to yield good qualitative agreement with the experiments. Overall our work opens the path to study collectives of self-rolling fibers as an interesting new class of active matter.
Source: arXiv (Cornell University)
Authors: Arnhold, Alex, Ziebert, Falko, Kulić, Igor M.
Language: English
Topic: Micro and Nano Robotics
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223027564