Piezoelectric microactuator with restraining layer for control of bending

摘要

A PZT microactuator such as for use in a hard disk drive has a restraining layer bonded on its side that is opposite the side on which the PZT will be mounted. The restraining layer comprises a stiff and resilient material such as stainless steel. The restraining layer can cover all of the top of the PZT, or most of the top of the PZT with an electrical connection being made to the PZT where it is not covered by the restraining layer. The restraining layer reduces bending of the PZT as mounted and hence increases effective stroke length, or reverses the sign of the bending which increases the effective stroke length of the PZT even further.

主权项

1. A piezoelectric microactuator comprising:
a piezoelectric material; opposite first and second faces of the piezoelectric microactuator; and a restraining layer having a Young's modulus of greater than 50 GPa bonded to the second face of the piezoelectric microactuator by an adhesive without any additional layer therebetween having a stiffness that is substantially less than the stiffness of the restraining layer, the restraining layer altering the bending behavior of the piezoelectric microactuator so as to increase the effective stroke length of the piezoelectric microactuator compared to what the stroke length of the piezoelectric microactuator would be in the absence of the restraining layer.