Slit Tubes for Semisoft Pneumatic Actuators

Lee Belding; Bilge Baytekin; Hasan Tarik Baytekin; Philipp Rothemund; Mohit S Verma; Alex Nemiroski; Dan Sameoto; Bartosz A Grzybowski; George M Whitesides

doi:10.1002/adma.201704446

Slit Tubes for Semisoft Pneumatic Actuators

Adv Mater. 2018 Mar;30(9). doi: 10.1002/adma.201704446. Epub 2018 Jan 15.

Authors

Lee Belding¹, Bilge Baytekin², Hasan Tarik Baytekin², Philipp Rothemund^{1

3

4}, Mohit S Verma¹, Alex Nemiroski¹, Dan Sameoto^{1

5}, Bartosz A Grzybowski², George M Whitesides^{1

6

4}

Affiliations

¹ Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA.
² Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.
³ School of Engineering and Applied Sciences, Harvard University, 29 Oxford St, Cambridge, MA, 02138, USA.
⁴ Kavli Institute for Bionano Science and Technology, Harvard University, 29 Oxford Street, Cambridge, MA, 02138, USA.
⁵ Department of Mechanical Engineering, University of Alberta, 9211-116 Street NW, Edmonton, Alberta, T6G 1H9, Canada.
⁶ Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford Street, Cambridge, MA, 02138, USA.

PMID: 29334140
DOI: 10.1002/adma.201704446

Abstract

This article describes a new principle for designing soft or 'semisoft' pneumatic actuators: SLiT (for SLit-in-Tube) actuators. Inflating an elastomeric balloon, when enclosed by an external shell (a material with higher Young's modulus) containing slits of different directions and lengths, produces a variety of motions, including bending, twisting, contraction, and elongation. The requisite pressure for actuation depends on the length of the slits, and this dependence allows sequential actuation by controlling the applied pressure. Different actuators can also be controlled using external "sliders" that act as reprogrammable "on-off" switches. A pneumatic arm and a walker constructed from SLiT actuators demonstrate their ease of fabrication and the range of motions they can achieve.

Keywords: external shells; pneumatic actuators; pneumatic artificial muscles; semisoft; sequential actuation; soft robotics.