This paper presents a large displacement, piezoelectric-metal structure actuator,
named the piezoelectric drum actuator. The drum actuator consists of a short,
thick-walled steel cylinder sandwiched by two thin composite disks, which are fabricated
from a brass disk bonded with a piezoceramic disk. The piezoceramic disk,
which is polarized in its thickness direction, has a large diameter thickness ratio, producing a large radial displacement under an applied voltage in the thickness, leading
to a large transverse deflection of the composite disks in the drum. The drum (outer
diameter: 12.0 mm) has a displacement that is about eight times larger than that of
a cymbal actuator made with the same ceramic material and comparable dimensions
under the same dc driving voltage of 270 V. The drum actuator also showed a large
resonance displacement of 56.7 μm under an ac voltage of 90 V. The effective piezoelectric
charge coefficient d
33 of the drum is about twice as large as that reported for
the cymbal.