Fast liquid-crystal elastomer swims into the dark

Miguel Camacho-Lopez, Heino Finkelmann, Peter Palffy-Muhoray, Michael Shelley

Research output: Contribution to journalArticle

Abstract

Liquid-crystal elastomers (LCEs) are rubbers whose constituent molecules are orientationally ordered. Their salient feature is strong coupling between the orientational order and mechanical strain1. For example, changing the orientational order gives rise to internal stresses, which lead to strains and change the shape of a sample. Orientational order can be affected by changes in externally applied stimuli such as light. We demonstrate here that by dissolving - rather than covalently bonding - azo dyes into an LCE sample, its mechanical deformation in response to non-uniform illumination by visible light becomes very large (more than 60° bending) and is more than two orders of magnitude faster than previously reported2-4. Rapid light-induced deformations allow LCEs to interact with their environment in new and unexpected ways. When light from above is shone on a dye-doped LCE sample floating on water, the LCE 'swims' away from the light, with an action resembling that of flatfish such as skates or rays. We analyse the propulsion mechanism in terms of momentum transfer.

Original languageEnglish (US)
Pages (from-to)307-310
Number of pages4
JournalNature Materials
Volume3
Issue number5
DOIs
StatePublished - May 2004

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Elastomers
Liquid Crystals
elastomers
Liquid crystals
liquid crystals
Azo Compounds
dyes
Azo dyes
Momentum transfer
Rubber
propulsion
rubber
doped crystals
stimuli
floating
Propulsion
residual stress
momentum transfer
Residual stresses
rays

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Camacho-Lopez, M., Finkelmann, H., Palffy-Muhoray, P., & Shelley, M. (2004). Fast liquid-crystal elastomer swims into the dark. Nature Materials, 3(5), 307-310. https://doi.org/10.1038/nmat1118

Fast liquid-crystal elastomer swims into the dark. / Camacho-Lopez, Miguel; Finkelmann, Heino; Palffy-Muhoray, Peter; Shelley, Michael.

In: Nature Materials, Vol. 3, No. 5, 05.2004, p. 307-310.

Research output: Contribution to journalArticle

Camacho-Lopez, M, Finkelmann, H, Palffy-Muhoray, P & Shelley, M 2004, 'Fast liquid-crystal elastomer swims into the dark', Nature Materials, vol. 3, no. 5, pp. 307-310. https://doi.org/10.1038/nmat1118
Camacho-Lopez M, Finkelmann H, Palffy-Muhoray P, Shelley M. Fast liquid-crystal elastomer swims into the dark. Nature Materials. 2004 May;3(5):307-310. https://doi.org/10.1038/nmat1118
Camacho-Lopez, Miguel ; Finkelmann, Heino ; Palffy-Muhoray, Peter ; Shelley, Michael. / Fast liquid-crystal elastomer swims into the dark. In: Nature Materials. 2004 ; Vol. 3, No. 5. pp. 307-310.
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