Electromechanical effect in freely suspended liquid crystal films

Abstract

Electromechanical effect in a freely suspended film based on 4-n-octyl-4′-cyanobiphenyl has been detected by means of light scattering at both the first and second harmonics of the exciting electric field. Experimental studies on voltage and frequency dependencies of the optical response are carried out. Organic solvent vapor is shown to strongly affect the electromechanical response. A feasible mechanism for the electromechanical effect is discussed.

Nonlinear generation of vorticity in thin smectic films

“…[7,8]. Smectic liquid crystals are remarkable layered materials which can form a rich variety of structures.…”

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.…”

Ferro- and Antiferroelectric Properties of Langmuir-Blodgett Films Composed of Mesogenic Bent-Core Molecules

“…chiral SmC * and achiral B 1 -B 7 phases) attract much attention of researchers. The ferro-and antiferroelectric properties in smectic C * phases of rod-like molecules were widely studied in both the conventional cell geometry [4,5] and in films: free-standing [6], spin-coated [7] and Langmuir-Blodgett ones [8]. On the other hand, the properties of thin…”