Net shape formed spiral and helical piezoelectric actuators

Piezoelectric actuators tend to be made from relatively simple shapes such as blocks, plates and beams. These shapes allow for a range of displacements from key actuation modes but, in order to expand this range, complex structures are required that cannot be made via conventional means. This study presents a novel manufacturing method for such structures using a green ceramic tape lamination process followed by plastic deformation. Furthermore, a helix and a spiral are introduced as examples of initially curved structures. Their actuated behaviour is described by simple but effective models in terms of the standard linear piezoelectric coefficients and is compared to experiments. It is shown that displacements are produced by actuation mechanisms not previously reported in the literature. (C) 2002 Kluwer Academic Publishers.