Stimuli-responsive cylindrical hydrogels mimic intestinal peristalsis to propel a solid object

Soft Matter. 2016 Apr 21;12(15):3582-8. doi: 10.1039/c5sm02553b.

Abstract

The emerging field of soft robotics relies on soft, stimuli-responsive materials to enable load transport, manipulation, and mobility in complex unconstrained environments. These materials often need to replicate biological functionality such as muscle contractions and flexibility. Here we demonstrate a soft actuator prototype based on thermosensitive PNIPAAM hydrogels that can transport and manipulate objects. A hollow cylindrical hydrogel was selectively heated and cooled with Peltier devices to yield a traveling wave of shrinking and swelling akin to intestinal peristalsis. A 4 mm diameter bead was placed inside the cylinder and propelled 19.5 mm, equal to distance traveled by the peristaltic wave. We derived conditions that enable peristaltic transport as a function of transporter-cargo design parameters. We conclude that hydrogel-based peristaltic manipulators covering 2 orders of magnitude in stiffness (1-10(2) kPa) could transport cargo spanning 4 orders of magnitude in size (μm-m).

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acrylic Resins / chemistry
  • Biomimetics / instrumentation
  • Biomimetics / methods*
  • Friction
  • Hydrogels*
  • Intestines / physiology
  • Motion*
  • Peristalsis*
  • Prostheses and Implants
  • Robotics
  • Temperature
  • Weight-Bearing

Substances

  • Acrylic Resins
  • Hydrogels
  • poly-N-isopropylacrylamide