Issue 24, 2017

Dual-responsive, shape-switching bilayers enabled by liquid crystal elastomers

Abstract

Materials that change shape are attractive candidates to replace traditional actuators for applications with power or size restrictions. In this work, we design a polymeric bilayer that changes shape in response to both heat and water by the incorporation of a water-responsive hydrophilic polymer with a heat-responsive liquid crystal elastomer. The distinct shape changes based on stimulus are controlled by the molecular order, and consequently the anisotropic modulus, of a liquid crystal elastomer. In response to water, the hydrophilic polymer layer expands, bending the bilayer along the path dictated by the anisotropic modulus of the liquid crystal elastomer layer, which is approximately 5 times higher along the molecular orientation than in perpendicular directions. We demonstrate that by varying the direction of this stiffer axis in LCE films, helical pitch of the swollen bilayer can be controlled from 0.1 to 20 mm. By spatially patterning the stiffer axis with a resolution of 900 μm2, we demonstrate bilayers that fold and bend based on the pattern within the LCE. In response to heat, the liquid crystal elastomer contracts along the direction of molecular order, and when this actuation is constrained by the hydrophilic polymer, this contraction results in a 3D shape that is distinct from the shape seen in water. Furthermore, by using the vitrification of the dry hydrophilic polymer this 3D shape can be retained in the bilayer after cooling. By utilizing sequential exposure to heat and water, we can drive the initially flat bilayer to reversibly shift between 3D shapes.

Graphical abstract: Dual-responsive, shape-switching bilayers enabled by liquid crystal elastomers

Supplementary files

Article information

Article type
Paper
Submitted
16 မတ် 2017
Accepted
21 ဧပြီ 2017
First published
25 ဧပြီ 2017

Soft Matter, 2017,13, 4349-4356

Dual-responsive, shape-switching bilayers enabled by liquid crystal elastomers

J. M. Boothby and T. H. Ware, Soft Matter, 2017, 13, 4349 DOI: 10.1039/C7SM00541E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements