Dual high-stroke and high-work capacity artificial muscles inspired by DNA supercoiling

Sci Robot. 2021 Apr 28;6(53):eabf4788. doi: 10.1126/scirobotics.abf4788.

Abstract

Powering miniature robots using actuating materials that mimic skeletal muscle is attractive because conventional mechanical drive systems cannot be readily downsized. However, muscle is not the only mechanically active system in nature, and the thousandfold contraction of eukaryotic DNA into the cell nucleus suggests an alternative mechanism for high-stroke artificial muscles. Our analysis reveals that the compaction of DNA generates a mass-normalized mechanical work output exceeding that of skeletal muscle, and this result inspired the development of composite double-helix fibers that reversibly convert twist to DNA-like plectonemic or solenoidal supercoils by simple swelling and deswelling. Our modeling-optimized twisted fibers give contraction strokes as high as 90% with a maximum gravimetric work 36 times higher than skeletal muscle. We found that our supercoiling coiled fibers simultaneously provide high stroke and high work capacity, which is rare in other artificial muscles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylic Resins
  • Artificial Organs*
  • Biomimetic Materials
  • Biomimetics
  • DNA, Superhelical*
  • Mechanical Phenomena
  • Miniaturization
  • Muscle, Skeletal*
  • Polyesters
  • Robotics*
  • Smart Materials
  • Tensile Strength

Substances

  • Acrylic Resins
  • DNA, Superhelical
  • Polyesters
  • Smart Materials
  • carbopol 940