Rotational Piezoelectric Actuator
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-26
Manipulation of probes and tools often requires very minute rotations which are difficult to produce, in particular under UHV conditions. The actuator consists of a circular piezoelectric disk 1 having a shaft 2 mounted at the disk's center hub 3 and a pair of radial slits 4, 5 arranged diametrically opposite one another. Top and bottom faces of disk 1 each carry four electrodes 6 through 9 providing four piezoelectric sectors, a through d (Fig. 1). Application of a voltage of alternating polarity to said sectors will result in a mechanical distortion of disk 1 (Fig. 2). The net effect of this distortion is a displacement of the center of mass of sectors a, b and d, c, respectively. Thus, a torque proportional to the velocity of displacement is exerted on shaft 2 mounted at the center hub 3 of disk 1.