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Yuchen Zhou, Milpitas US

Yuchen Zhou, Milpitas, CA US

Patent application numberDescriptionPublished
20080221432Low temperature method to enhance detection of magnetic beads - Detection of magnetic beads at temperature below room temperature can increase the signal level significantly as compared to the same detection when performed at room temperature. Additional improvement is obtained if the beads are below 30 nm in size and if deviations of bead size from the median are small. A preferred format for the beads is a suspension of super-paramagnetic particles in a non-magnetic medium.09-11-2008
20090021868Perpendicular magnetic recording head with a laminated pole - A laminated write pole layer for a PMR write head is disclosed in which a plurality of “n” magnetic layers and “n−1” non-magnetic spacers are formed in an alternating fashion on a substrate. The non-magnetic spacers promote exchange decoupling or antiferromagnetic coupling between adjacent magnetic layers. Writability is improved when the trailing magnetic layer has a thickness greater than the thickness of other magnetic layers and preferably >25% of the total thickness of the magnetic layers. The thicknesses of the other magnetic layers may be equal or may become progressively smaller with increasing distance from the trailing magnetic layer. In another embodiment, the non-magnetic spacer between the trailing magnetic layer and the nearest magnetic layer is replaced by a magnetic spacer made of a soft magnetic material to promote magnetic coupling and effectively increase the thickness of the trailing magnetic layer.01-22-2009
20090034130Shield design for magnetic recording head - A magnetic shield in which all domain patterns and orientations are stable and which are consistently repeated each time said shield is exposed to an initialization field, is disclosed. This has been achieved by giving it a suitable shape which ensures that all closure domains can align themselves at a reduced angle relative to the initialization direction while still being roughly antiparallel to one another. Most, though not all, of these shapes are variations on trapezoids.02-05-2009
20090052092Perpendicular magnetic recording head laminated with AFM-FM phase change material - A PMR writer is disclosed that minimizes pole erasure during non-writing and maximize write field during writing through an AFM-FM phase change material that is in an AFM state during non-writing and switches to a FM state by heating during writing. The main pole layer including the write pole may be comprised of a laminated structure having a plurality of “n” ferromagnetic layers and “n-1” AFM-FM phase change material layers arranged in an alternating manner. The AFM-FM phase change material is preferably a FeRh or FeRhX alloy (X=Pt, Pd, or Ir) having a Rh content >35 atomic %. AFM-FM phase change material may also be used as a flux gate to prevent yoke flux from leaking into the write pole tip. Heating for the AFM to FM transition is provided by write coils and/or a coil located near the AFM-FM phase change material to enable faster transition times.02-26-2009
20090065359Discrete contact MR bio-sensor with magnetic label field alignment - The invention describes a family of sensors for assaying macro-molecules and/or biological cells in solution. Each sensor has the form of a well (a hollow cylinder having a floor but no lid) or a trench whose walls comprise a plurality of GMR or TMR devices. Suitably shaped magnets located below each well's floor pull labeled particles into the well/trench and up against the inner wall where a field gradient orients them for optimum detection. Any unattached labels that happen to also be in the well/trench are removed through suitably sized holes in the floor.03-12-2009
20090139908Guided transport of magnetically labeled biological molecules and cells - Presented herein is a method and devices for identifying biological molecules and cells labeled by small magnetic particles and by optically active dyes. The labeled molecules are typically presented in a biological fluid but are then magnetically guided into narrow channels by a sequential process of magnetically trapping and releasing the magnetic labels that is implemented by sequential synchronized reversing the magnetic fields of a regular array of patterned magnetic devices that exert forces on the magnetic particles. These devices, which may be bonded to a substrate, can be formed as parallel magnetic strips adjacent to current carrying lines or can be substantially of identical structure to trilayered MTJ cells. Once the magnetically labeled molecules have been guided into the appropriate channels, their optical labels can be detected by a process of optical excitation and de-excitation. The molecules are thereby identified and counted.06-04-2009
20090257151Thin seeded Co/Ni multilayer film with perpendicular anisotropy for spintronic device applications - A spin valve structure for a spintronic device is disclosed and includes a composite seed layer made of at least Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (Co/Ni)10-15-2009
20100117641DETECTION OF MAGNETIC BEADS USING A MAGNETORESISTIVE DEVICE TOGETHER WITH FERROMAGNETIC RESONANCE - A method and apparatus for detecting the presence of magnetic beads is disclosed. By providing both a static magnetic field and a magnetic field that alternates in the MHz range, or beyond, the bead can be excited into FMR (ferromagnetic resonance). The appearance of the latter is then detected by a magneto-resistive type of sensor. This approach offers several advantages over prior art methods in which the magnetic moment of the bead is detected directly.05-13-2010
20100231214DETECTION OF MAGNETIC BEADS USING A MAGNETORESISTIVE DEVICE TOGETHER WITH FERROMAGNETIC RESONANCE - A method and apparatus for detecting the presence of magnetic beads is disclosed. By providing both a static magnetic field and a magnetic field that alternates in the MHz range, or beyond, the bead can be excited into FMR (ferromagnetic resonance). The appearance of the latter is then detected by a magneto-resistive type of sensor. This approach offers several advantages over prior art methods in which the magnetic moment of the bead is detected directly.09-16-2010
20110013321Enhanced hard bias in thin film magnetoresistive sensors with perpendicular easy axis growth of hard bias and strong shield-hard bias coupling - A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.01-20-2011
20110014390Enhanced hard bias in thin film magnetoresistive sensors with perpendicular easy axis growth of hard bias and strong shield-hard bias coupling - A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.01-20-2011
20110043201DETECTION OF MAGNETIC BEADS USING A MAGNETORESISTIVE DEVICE TOGETHER WITH FERROMAGNETIC RESONANCE - A method and apparatus for detecting the presence of magnetic beads is disclosed. By providing both a static magnetic field and a magnetic field that alternates in the MHz range, or beyond, the bead can be excited into FMR (ferromagnetic resonance). The appearance of the latter is then detected by a magneto-resistive type of sensor. This approach offers several advantages over prior art methods in which the magnetic moment of the bead is detected directly.02-24-2011
20110095751Detection of magnetic beads using a magnetoresistive device together with ferromagnetic resonance - A method and apparatus for detecting the presence of magnetic beads is disclosed. By providing both a static magnetic field and a magnetic field that alternates in the MHz range, or beyond, the bead can be excited into FMR (ferromagnetic resonance). The appearance of the latter is then detected by a magneto-resistive type of sensor. This approach offers several advantages over prior art methods in which the magnetic moment of the bead is detected directly.04-28-2011

Patent applications by Yuchen Zhou, Milpitas, CA US