Sae Magnetics (h.k.) Limited

Nanyang Technological University

Sae Magentics (h.k.) Ltd.

Zhihong Wang

Masashi Shiraishi

Kai Wu

Tamon Kasajima

Weiguang Zhu

Ping Shang

Ooi Kiang Tan

Xi Yao

Changlei Zhao

Chen Chao

A process to produce dense nanocrystalline composites such as ceramic bodies, coatings and multi-layered devices with uniform microstructure is disclosed. The invention utilizes sol-gel solutions to reduce agglomeration of nanocrystalline powders in the production of 'green bodies' or intermediate products. This novel use of sol-gel solutions also reduces grain growth and porosity in products during sintering. In finished products, final grain sizes are typically less than 100 nm with densities of the final products approaching 99.5% of theoretical densities. In addition, sintering temperatures required are lower than those in conventional methods, typically less than 1,100&#xb0; C. While FIG.shows one application of this novel process, this invention has wide application in the manufacture of many other products, particularly for composite coatings and in the production of nanodevices.

Process for producing nanocrystalline composites

An interferometer has a source for generating a first beam and a second beam of a coherent monochromatic light having a wavelength &#x3bb;, optical elements for directing the beams through two different optical paths having a path-length difference, a detector for detection of an interference signal of the beams, and a modulator for additionally varying the path-length difference periodically to allow the interference signal be detected near a path-length difference of &#x3bb;/4 periodically. A maximum intensity change in the interference signal caused by a small period change of the path-length difference is thus detectable. The maximum intensity change caused by varying the path-length difference by at least &#x3bb;/2 may also be detectable. The interferometer may be used to measure small vibrations, without pre-calibration and/or a feedback servo system for keeping the path-length difference near &#x3bb;/4.

Method of interferometry with modulated optical path-length difference and interferometer

A piezoelectric actuator is disclosed including an annular piezoelectric element and a base. There is a gap along the radial direction of the annular piezoelectric element. One of the two ends, i.e., the fixed end of the said annular element, is connected to the base, while the other end is free. The base is made of piezoelectric materials. Furthermore, the annular element is divided into two or more annular parts along the direction of its circumference by the electrode patterns applied on its two opposite surface and/or its polarization directions. When driving voltages are applied, the actuator can generate roughly a rotary motion around the center of the annular piezoelectric element. The annular rotary actuator could be either a single plate or with multilayer structure. The present invention further relates to a dual stage head positioning actuator system of a hard disk drive with a plurality of disks and a plurality of vertically aligned head sliders mounted on distal ends of a plurality of suspensions via the annular piezoelectric actuators.

Dual stage actuator systems for high density hard disk drives using annular rotary piezoelectric actuators

A piezoelectric device comprises an integral body of piezoelectric material having a length and width greater than its thickness; wherein the device further includes, in contact with the body, respective pairs of electrodes, wherein the electrodes of each pair are opposed in the thickness direction, wherein the body deflects along said transverse direction when a voltage is applied to the electrode pair. The present invention further provisdes a disk drive suspension and a head gimbal assembly.

Head gimbal assembly with piezoelectric microactuator

Growing community of inventors

Singapore, Singapore

Zhihong Wang