{
  "abstract": "Elongate multi-legged robots use coordinated body waves and distributed legs to move through cluttered terrestrial environments. However, as housing actuators for independent leg control can require bulky body segments, their non-streamlined body and limb structure makes it difficult to achieve swimming capability comparable to their terrestrial locomotor performance. At the water surface, we found that the multi-legged robots we tested unexpectedly moved backward: their body waves traveled in the same direction as their displacement, i.e., swimming with a direct wave. We found similar behavior in the centipede \\textit{Lithobius forficatus}, which swims with a direct body wave and periodic leg movement. To study how distributed legs contribute to direct-wave swimming, we analyze animal kinematics and develop a multi-legged robophysical model that allows independent variation of leg morphology and stiffness, body-wave direction, and leg coordination. Robophysical experiments show that direct body waves produce consistent forward motion under the tested conditions and that swimming performance depends on body--leg coordination. Additionally, directionally compliant legs increase displacement from approximately 0.08 to 0.21 body lengths per cycle relative to rigid legs under matched anti-phase actuation. These findings clarify how distributed appendages contribute to surface swimming and establish gait and morphology design principles for extending multi-legged field robots from terrestrial locomotion into aquatic environments.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.27088",
  "author_total": 7,
  "authors": [
    {
      "name": "Zhaochen J. Xu"
    },
    {
      "name": "Delfin Aydin"
    },
    {
      "name": "Abdullah Mustafa"
    },
    {
      "name": "Margarita B. Levin"
    },
    {
      "name": "Jianfeng Lin"
    },
    {
      "name": "Tianyu Wang"
    },
    {
      "name": "Daniel I. Goldman"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8cehevyj3fa4n.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.27088",
  "fulltext_url": null,
  "id": "8cehevyj3fa4n",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.27088",
  "language": null,
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cs.RO"
    ],
    [
      "arxiv",
      "physics.bio-ph"
    ],
    [
      "openalex",
      "2204|Robotic Locomotion and Control"
    ]
  ],
  "openalex": "W7214238909",
  "pdf_url": "https://arxiv.org/pdf/2609.27088",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-22",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8cehevyj3fa4n.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:37Z",
      "native_id": "2609.27088",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.27088"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.bio-ph",
      "subfield": "biological-medical"
    }
  ],
  "title": "Water Surface Swimming in a Centipede and its Robophysical Model",
  "title_text": "Water Surface Swimming in a Centipede and its Robophysical Model",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:37Z",
  "url": "https://research.draconitic.com/paper/8cehevyj3fa4n",
  "venue": "arXiv",
  "versions": []
}