Piezoelectric actuators and motors based on shell structures

A design consisting of an elliptical metal shell whose long axis is occupied by prestressed multilayer actuators can be applied to a large variety of piezoelectric structures to offer compact, low-voltage actuation at operating frequencies that range from DC to 40 kHz. The useful motion or vibration is recovered in the transverse direction, at the extremities of the short axis. The elliptical shell serves as an amplification mechanism. Its dimensions determine the output characteristics of the device in terms of strain, force and resonance frequency. This paper presents the design of three structures based on this concept. 3D finite element analysis result as well as experimental measurements are presented.