A data storage device includes a stack of discs mounted on a spindle and a pivot block rotatably mounted around a shaft. The data storage device also includes an arm having first and second ends, with the first end supporting a head and the second end movably attached to the pivot block. The data storage device further includes an ultrasonic piezoelectric actuator that moves the arm along the pivot block to enable the head to interact with data storage surfaces of the discs.

A multi-layer piezoelectric microactuator assembly has at least one poled and active piezoelectric layer and one poled but inactive piezoelectric layer. The poled but inactive layer acts as a constraining layer in resisting expansion or contract of the first piezoelectric layer thereby reducing or eliminating bending of the assembly as installed in an environment, thereby increasing the effective stroke length of the assembly. Poling only a single layer would induce stresses into the device; hence, polling both piezoelectric layers even though only one layer will be active in use reduces stresses in the device and therefore increases reliability.

According to one embodiment, a disk device includes a magnetic disk, a magnetic head, a flexure, a piezoelectric element, a first bonding material, a second bonding material, and a protrusion. The flexure includes a first outer surface, a first pad, and a second pad. The first pad and the second pad are on the first outer surface. The piezoelectric element includes a second outer surface, a first electrode, and a second outer surface. The first electrode and the second electrode are on the second outer surface. The first bonding material, which is conductive, bonds the first pad and the first electrode. The second bonding material, which is conductive, bonds the second pad and the second electrode. The protrusion is provided on the flexure, is located at least partially between the first bonding material and the second bonding material, and protrudes from the first outer surface.

In a multi-actuator drive, the effect of moving a first actuator (the so-called “aggressor actuator”) in on a second actuator (the so-called “victim actuator”) is reduced or compensated for. A victim feedforward signal is added to a microactuator control signal of the victim actuator in response to a voice-coil motor (VCM) control signal that is applied to the aggressor actuator. The feedforward signal is configured to compensate for disturbances to the victim microactuator caused by VCM commands provided to the aggressor actuator. The feedforward signal is based on a transfer function that models commands added to the victim microactuator, which is coupled to the head of the victim actuator, as a function of the aggressor VCM control signal applied to the aggressor actuator.

A method of manufacturing a piezoelectric microactuator having a wrap-around electrode includes forming a piezoelectric element having a large central electrode on a top face, and having a wrap-around electrode that includes the bottom face, two opposing ends of the device, and two opposing end portions of the top face. The device is then cut through the middle, separating the device into two separate piezoelectric microactuators each having a wrap-around electrode.

According to one embodiment, a suspension assembly includes a support plate including a distal end and a proximal end portion, a wiring member including a gimbal portion and provided on the support plate, and a magnetic head mounted on the gimbal portion. The gimbal portion includes a first end portion located on a side of the proximal end portion with respect to the magnetic head and welded to the support plate, a second end located on a side of the distal end portion with respect to the magnetic head and welded to the support plate, a tongue portion on which the magnetic head is mounted, located between the first end portion and the second end portion, and supported so as to be displaceable relative to the support plate, and a limiter opposing the tongue portion with a gap.

A brake crawler for an elevator-type hard disk drive generally includes a first and second set of clamp arms vertically arranged, each of the first and second sets of clamp arms being capable of exerting a clamping force on a shaft or slider via activation or deactivation of an actuator element associated with each set of clamp arms. The brake crawler further includes an actuator element disposed between the first and second set of clamp arms which allows for movement of the first set of clamp arms away from the second set of clamp arms upon a change in state of the actuator element. Via a specific sequence of activating and deactivating various of the actuator elements associated with the brake crawler, the brake crawler is capable of inch worm-type movement up and down the shaft.

A device disclosed herein includes an upper shape memory alloy (SMA) wire, a lower SMA wire, a flexure having an opening, and a spring configured within the flexure opening, wherein the lower SMA wire, and the flexure are attached at one end to an anchor and at another end to a pin.

According to one embodiment, a magnetic disk device including a disk, a head that writes data to the disk and reads data from the disk, an actuator that is rotationally driven and controls movement of the head mounted above the disk, a microactuator that is mounted on the actuator and finely swings the head in a radial direction of the disk by a piezoelectric element that extends and contracts when a drive voltage based on a bias voltage is applied to the piezoelectric element, and a controller that switches the bias voltage according to an operation state during an access process.

A PZT microactuator such as for a hard disk drive has a restraining layer bonded on its side that is opposite the side on which the PZT is mounted. The restraining layer comprises a stiff and resilient material such as stainless steel. The restraining layer can cover most or all 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. The restraining layer can be one or more active layers of PZT material that act in the opposite direction as the main PZT layer. The restraining layer(s) may be thinner than the main PZT layer.