Experimental model and ic-process design of a nanometer linear piezoelectric stepper motor

A linear stepper motor capable of sub-micrometer controlled movement, or nano-actuation, has been constructed usingthe piezoelectric materiallead-zirconate-titanate (PZT). This prototype deviceconsists of a piezoelectric driving element measuring 25.4mm × 12.7mm × 1.6 mm. This device is inset in a trench to constrain motionto one dimension. An electrode on the bottom of the glider is used with an electrode on the top of thetrenchto implement an electrostatic clamp. A linearinertial sliding motion canbe achieved by rapidly expanding or contracting the piezoelectric bar which is connected between a glider and an attached base. Glider velocities of 5.7-476¼m/s were measured by timingthe movement of the gliderover a 1.0mm portion of the track through an optical microscope. Displacement steps of 70-1100nm were calculated by dividing the measured glider velocity by the frequency of the applied voltage pulses. Displacement step size and glider velocity were controlled by the application of PZT extension voltages ranging from ±(60-340) V. The ability of the current prototype piezoelectric steppermotorto implement sub-micrometer motion with the large (centimeter) travel distances may have applications to electron microscopy, scanning tunneling microscopy, alignment of optical fibers, and magnetic recording. This motor has been constructed as a prototype of a version that is being integrated on a silicon wafer and a fabrication process designis given.