May 24, 2005Advanced Liquid Crystal Technologies, Inc.

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Liquid Crystalline Elastomers as Artificial Muscles

P.E. Cladis

Advanced Liquid Crystal Tech.

Summit, NJ 07902-1314

May 24, 2005Advanced Liquid Crystal Technologies, Inc.

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Stress-Strain in Smectic A SLCEsStrasbourg ILCC 1998 – Nicole Assfalg

Alumni from Heino Finkelmann's Group

See also: Liquid crystalline elastomers as artificial muscles

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Spontaneous Shape Change: Sample Preparation

P.E. Cladis: Phase Transitions in Liquid Crystalline Elastomers:A Fundamental Aspect of LCEs as Artificial Muscles in Interactive Dynamics of Convection and Solidification, P. Erhard, D.S. Riley and P.H. Steen (eds), Kluwer Academic Publishers, Dordrecht (2001) p. 123.

May 24, 2005Advanced Liquid Crystal Technologies, Inc.

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Spontaneous Shape Change: Result

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Goal

1998 Symposium on Artificial Muscles and Liquid

Crystalline ElastomersPartially supported by NSF DMR 9871475

http://alct.com/fps/index.htm

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First works

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Graduation

First Results: Thin samples

Kyushu University 2001

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Swelling Dynamics: Samples

PR E 69, 021710 (2004) Swelling dynamics of liquid crystal

elastomers swollen with low molecular weight liquid crystals

Yusril Yusuf,* Y. Ono, Y. Sumisaki, P. E. Cladis†, H. R. Brand, H.Finkelmann,Shoichi Kai‡

Sample 5CB & MBBA swelling agent

Monomer and Polydomain LCEsFrom Heino Finkelmann’s Lab

150μm thick, 1x0.5mm2

Viewed in Polarizing Microscope

Swollen Nematic LSCE

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MONO1

Dimension || n does not change!PR E 69, 021710 (2004)

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MONO2 and POLY

PR E 69, 021710 (2004)

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Picture

PR E 69, 021710 (2004)

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Swelling Dynamics

POLY:

5CB ~8min

MBBA ~6min

MONO:

5CB ~16min

MBBA ~30min

Inverse swelling ratio

PR E 69, 021710 (2004)

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Swelling Temperature Dependence

Temperature dependence

None for Dry POLY

Lots for MONO and Swollen POLY

PR E 69, 021710 (2004)

MO

NO

1PO

LY

�Dry

swollen

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Electric Field

Yusuf et al. PRE 71, 061702 (2005)

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Voltage Dependence

Yusuf et al. Low-voltage-driven electromechanical effects of

swollen liquid-crystal elastomers ...

Threshold about 1.5V independent of sample thickness – typical for LMWLCs

Better reorientation, larger shape change – cf Slide 8

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Temperature Dependence

Yusuf et al. PR E June 2005

MONO1 – maximum δdepends on sample thickness,

here about 20μmMONO2 – δ∼0

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Characteristic Times, τ

Yusuf et al. PR E June 2005

Switch on Switch off

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Voltage Dependence of 1/τ

Yusuf et al. PR E June 2005

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Voltage Summary

Yusuf et al. PR E June 2005

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Acknowledgements

We thank the IMA for the opportunity to present these results.Yusril Yusuf,* Y. Ono, Y. Sumisaki, Jong-Hoon Huh, H. R. Brand, H.Finkelmann, Shoichi Kai‡

Nicole Assfalg

PEC thanks the Japan Society for the Promotion of Sciences for a Research Prize enabling this research.

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Kyushu 3/2001