Development of microactuators driven by liquid crystals (6th report, control of driving direction)

Abstract

We have developed liquid crystalline microactuators which can drive in two or four ways. These actuators consist simply of two glass plates on which patterned electrodes and alignment layers have been treated. For a 2-way actuator, the glass plate is divided into two areas which have positive and negative tilt angles of molecular orientation, respectively; the rotational directions of molecules are opposite to each other, so that when an electric field is applied to one area the actuator moves forward, whereas it moves backward when an electric field is applied to the other area. For a 4-way actuator, hybrid molecular orientation mode is employed and four separated electrodes are patterned only on the upper glass plate; four electrodes correspond to forward, backward, rightward, and leftward movements, respectively. Comparison of the driving speeds of these two actuators with that of a 1-way actuator shows that the driving speed of a 2-way actuator is a half of that of a 1-way actuator, since only a half area of a glass plate contributes to driving forward or backward for a 2-way actuator. The driving speed of a 4-way actuator is much less than 1/4 of that of a 1-way actuator because of the hybrid molecular orientation mode.