A new type of linear piezoelectric stepper motor

A new type of linear piezoelectric stepper motor combining the piezoelectric effect with the electrorheological (ER) effect as studied. The ER effect occurred in fluids that can make a transition from the liquid state to a weak solid state reversibly controlled by an electric field. The driving device of a piezomotor consists of a bilayer piezoactuator using PMN-PNN-PZT ceramics, an ER fluid clamp, and a grid base. Compared with conventional piezoelectric motors, it has unique advantages: no vibration noise, zero wear, low power consumption, large travel range, high mechanical resolution, etc. It will be used widely in the field of precise micropositioners particularly, such as STM, alignment of optical fibers, biological cell operation, and semiconductor manufacture techniques, etc. A motor with an inchworm velocity of about 1.5 /spl mu/m/s and pulse force of about 0.25 kgf was obtained.<
>