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.

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.

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.

Various illustrative aspects are directed to a data storage device comprising one or more disks; an actuator arm assembly comprising one or more actuator arms, and configured to position the one or more actuator arms over disk surfaces of the one or more disks; one or more fine actuators, disposed on the one or more actuator arms; and one or more processing devices. The one or more processing devices are configured to: output a driver current to the one or more fine actuators, wherein the one or more processing devices are configured to rate limit a rise of the driver current over time during an activation of the driver current to within a selected rate limit of current rise over time.

Various embodiments of the present disclosure provide a read/write device for a hard-disk memory system. The read/write device includes a fixed structure; a membrane region including a first and a second membrane, which are constrained to the fixed structure, and a central portion, interposed between the first and second membranes; a first and a second piezoelectric actuator, mechanically coupled, respectively, to the first and second membranes; and a read/write head, which is fixed to the central portion of the membrane region. The first and second piezoelectric actuators can be controlled so as to cause corresponding deformations of the first and second membranes, said deformations of the first and second membranes causing corresponding movements of the read/write head with respect to the fixed structure.

An electrical connection structure for connecting a piezoelectric element and an electrical circuit to each other with a conductive adhesive is described. The electrical connection structure includes an epoxy, a conductive component surrounded by the epoxy, and a trace feature implemented on top of the electrical connection structure. At least one depression feature can be implemented on top of the electrical connection structure to constrain the epoxy and the at least one conductive component.

Various embodiments of the present disclosure provide a read/write device for a hard-disk memory system. The read/write device includes a fixed structure; a membrane region including a first and a second membrane, which are constrained to the fixed structure, and a central portion, interposed between the first and second membranes; a first and a second piezoelectric actuator, mechanically coupled, respectively, to the first and second membranes; and a read/write head, which is fixed to the central portion of the membrane region. The first and second piezoelectric actuators can be controlled so as to cause corresponding deformations of the first and second membranes, said deformations of the first and second membranes causing corresponding movements of the read/write head with respect to the fixed structure.

A thin-film piezoelectric-material element includes a laminated structure part having a lower electrode film, a piezoelectric-material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric-material film, a lower piezoelectric-material protective-film being formed with alloy material, and an upper piezoelectric-material protective-film being formed with alloy material. The piezoelectric-material film includes a size larger than the upper electrode film, a riser end-surface and step-surface formed on a top-surface of the upper electrode film side. The riser end-surface connects smoothly with a peripheral end-surface of the upper electrode film and vertically intersects with the top-surface. The step-surface intersects vertically with the riser end-surface. The lower piezoelectric-material protective-film, and the upper piezoelectric-material protective-film are formed with alloy material including Fe as main ingredient and having Co and Mo, by Ion beam deposition.

A flexure assembly is described. The flexure assembly includes a gimbal portion on configured to receive a slider. The gimbal portion includes a first surface and a second surface which is opposite to the first surface. The slider is mounted on the second surface. The flexure assembly also includes a pair of microactuator elements. The flexure assembly also includes a tongue of the gimbal portion on which the slider is mounted. The tongue includes a dimple point which represents the center of the tongue. The flexure assembly also includes a pair of first supporting portions and a pair of second supporting portions of the gimbal portion. A pair of end portions are individually secured to the tongue and the first supporting portions and the pair of second supporting portions. The flexure assembly also includes a conductive circuit portion unsupported between a first stationary part and the pair of end portions.

A head stack assembly for a hard disk drive includes a head gimbal assembly. The head gimbal assembly includes a slider, a plurality of microactuators, and a microactuator controller. The slider includes active components which are configured to perform drive operations in response to receiving control signals from a drive controller. The microactuators are configured to adjust the position of the slider relative to a magnetic disk during drive operations. The microactuator controller is configured to selectively couple the microactuators to a microactuator power source based on the control signals.