Publication Title

Physical Review Letters

Publication Date

10-13-2006

Document Type

Article

DOI

10.1103/PhysRevLett.97.157802

Keywords

dell, piezoelectricity, coefficients

Disciplines

Physics

Abstract

Flexoelectricity is a coupling between orientational deformation and electric polarization. We present a direct method for measuring the flexoelectric coefficients of nematic liquid crystals (NLCs) via the electric current produced by periodic mechanical flexing of the NLC's bounding surfaces. This method is suitable for measuring the response of bent-core liquid crystals, which are expected to demonstrate a much larger flexoelectric effect than traditional, calamitic liquid crystals. Our results reveal that not only is the bend flexoelectric coefficient of bent-core NLCs gigantic (more than 3 orders of magnitude larger than in calamitics) but also it is much larger than would be expected from microscopic models based on molecular geometry. Thus, bent-core nematic materials can form the basis of a technological breakthrough for conversion between mechanical and electrical energy.

Comments

Copyright 2006 American Physical Society. Available on publisher's site at http://dx.doi.org/10.1103/PhysRevLett.97.157802


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