Measurement of Electrically Induced Vibration Profile in Freely Suspended Film of Ferroelectric Liquid Crystal

A mechanical vibration profile of a freely suspended film of a ferroelectric liquid crystal induced by applying a sinusoidal electric field is observed using a laser Doppler vibrometer. Mechanical resonance profiles of the freely suspended diaphragm are represented in the form of mechanical vibration distributions. The number of modes in the mechanical vibration increases with frequency. The peak displacement decreases with frequency and the magnitude is of the order of 0.8 µm under the application of 100 V/mm. The vibration displacement is proportional to the electric field applied to the liquid crystal diaphragm existing between two parallel electrodes. The observed mechanical displacements are due to the resonance of the freely suspended diaphragm, which is essential for the construction of a membrane device in relation to light beam reflection.