A novel drum piezoelectric-actuator

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: 12.0mm) 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 270V. The drum actuator also showed a large resonance displacement of 56.7μm under an ac voltage of 90V. The effective piezoelectric charge coefficient d'33 of the drum is about twice as large as that reported for the cymbal.