Molecular reorientation and deformation of a freely suspended ferroelectric liquid crystal film

Abstract

A study of the deformation of a freely suspended ferroelectric liquid crystal film induced by an alternating electric field has been carried out. A notable peak of the magnitude of the deformation was observed at the damping frequency of the molecular reorientation. A deformation that depends on the polarity of the applied field was observed in the frequency range higher than the damping frequency of the molecular reorientation.

Optomechanical effect in ferroelectric liquid crystal freely suspended films

“…2,3,5 In this case the azimuthal motion of the liquid crystal director driven by alternating electric field is accompanied by, socalled backflow, which induces a viscous stress disturbing the surface of the film. 26 The periodical displacement of the film surface results in deflection of the probing beam of lowpower He-Ne laser, as shown in the inset of Fig.…”

“…Use of a ferroelectric liquid crystal has a considerably simplified a way of excitation of bending vibration in freely suspended film. [2][3][4][5] …”

“…[1][2][3][4][5] Such a film is considered as perfect membrane, whose vibrational motion depends only on the film geometry, isotropic surface tension and homogeneous two-dimensional density ͑including the inertia of the air moving with the film͒. [6][7][8][9] Change in any of these parameters strongly influences resonant properties of the vibrating film, for example, the pressure gauge employing freely suspended film was shown to indicate the change of air pressure by of only 0.5 Torr.…”

Ellipsometry of Molecular Reorientation in a Freely Suspended Ferroelectric Liquid Crystal Film

“…Freely suspended (FS) film of ferroelectric liquid crystal (FLC) has layered structure and thickness of the film can be varied from only two layers to more than several hundreds layers, so that freely suspended ferroelectric liquid crystal film (FSFLC) has recently been investigated as thin two-dimensional liquid crystal system [ 1-31. In addition, several interesting electrooptical properties of a thick FS film that is thicker than helical pitch has been reported [4,5]. In this article, ellipsometric study of molecular motion of the thick FS film has been carried out.…”

Electromechanical effect in freely suspended liquid crystal films

“…The mechanical vibration of the surface of FLC freely suspended film was effectively excited by a lateral alternating electric field and studied by means of light scattering at the frequency of applied electric field. [8][9][10] Recently, a linear EM effect has also been detected in a bilayer lipid membrane. 11 However, the linear EM effect has never been observed in FS films based on thermotropic achiral LC.…”