Material-based modeling of cavatappi artificial muscles

Diego R. Higueras-Ruiz, Heidi P. Feigenbaum, Michael W. Shafer

Research output: Contribution to journalArticlepeer-review


Soft actuators show much promise for use in bioinspired and biomimetic robotics as they share many similarities with actuation systems found in nature. Twisted and coiled actuators are soft actuators that have been shown to outperform many metrics of biological muscles, leading researchers to derive actuation models for future control and implementation. Although models have been proposed for twisted and coiled carbon nanotubes and polymer fibers, cavatappi artificial muscles—a novel twisted and coiled fluidic soft actuator—have not been modeled yet. This work establishes a framework for modeling cavatappi using the thick-wall pressure vessel stress analysis and the spring theory. The presented model uses the mechanical properties of the precursor drawn material used for fabrication, initial twist (internal fiber angle), muscle geometry, and internal pressure to predict the artificial muscles contraction under different external loads. The model predictions agree with the experimental results for cavatappi of different internal fiber angles and load conditions. Given their potential implementation in bioinspired applications, our model can help better design, optimize, and control the actuation response of cavatappi.

Original languageEnglish (US)
Article number125021
JournalSmart Materials and Structures
Issue number12
StatePublished - Dec 2022


  • artificial muscles
  • biomimetic
  • soft actuator

ASJC Scopus subject areas

  • Signal Processing
  • Civil and Structural Engineering
  • Atomic and Molecular Physics, and Optics
  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Electrical and Electronic Engineering


Dive into the research topics of 'Material-based modeling of cavatappi artificial muscles'. Together they form a unique fingerprint.

Cite this