A multilayer inplane bending piezoelectric actuator for dual-stage head-positioning control system

A novel multilayer in-plane bending piezoelectric actuator, called a multilayer split-morph, was designed and fabricated by thick-film screen-printing technology for a dual-stage head-positioning actuator system in a hard disk drive. The design, operation and theoretical principles have been described. The electromechanical performance of the fabricated actuators has been evaluated. The actuation stroke of the actuator is in inverse proportion to the thickness of the piezoelectric layer. The highest displacement/voltage sensitivity of 0.154µmV^-1 is achieved in a trapezoidal multilayer split-morph with a thickness of 35 m in each piezoelectric layer. The corresponding fundamental resonance frequency of the sway mode is high at 47 kHz in the trapezoid actuator with dimensions of 10.14 mm length, 3.08 mm and 1.54 mm widths of the two parallel sides of the trapezoid. The multilayer split-morph was designed to integrate directly onto a modified suspension load beam. With the combined attractive performances indicated above, the batch fabricated multilayer split-morph can provide a low-cost but promising solution for achieving very high track densities in a hard disk drive by implementing a high performance dual-stage head-positioning actuator system.