Nematic Anisotropic Liquid-Crystal Gels—Self-Assembled Nanocomposites with High Electromechanical Response
✍ Scribed by C. Huang; Q.M. Zhang; A. Jákli
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 166 KB
- Volume
- 13
- Category
- Article
- ISSN
- 1616-301X
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✦ Synopsis
Abstract
The uniqueness of liquid crystals (LCs) lies in the large anisotropies of their properties, which can be utilized to generate high electromechanical responses. In a properly oriented LC polymer system, an external electric field can induce reorientation of the mesogenic units possessing a dielectric anisotropy, which, when coupled with the shape anisotropy of the mesogenic units, can in turn produce large mechanical strain. Anisotropic LC gels, which can be obtained by in‐situ photopolymerization of the reactive LC molecules in the presence of non‐reactive LC molecules in an oriented state, are an example of such liquid‐crystal polymer systems. It is shown here that a homeotropically aligned LC gel in its nematic phase exhibits high electrically induced strain (> 2 %) with an elastic modulus of 100 MPa and a high electromechanical conversion efficiency (75 %) under an electric field of 25 MV/m. These anisotropic LC polymeric materials could provide a technologically compatible system for such applications as artificial muscles and as microelectromechanical devices.