The invention pertains to a head-disk assembly device, “mass spin-valve” or “gravitational rectifier” and method of producing gravitomagnetic induction utilizing Nano-features; Nano-bumps and Nano-pits; fabricated on the surface of a hard disk. The device includes a computer hard disk; a piezoelectric glide head and/or a GMR read head; a typical hard drive’s electronics; wherein, defects are fabricated on the said disk using a Focused Ion Beam (FIB) by depositing requisite number of nanobumps of specified height, and etching equal number of nanopits of specified depth a few mils or mm apart on a pre-decided radius. By spinning the said nano-features disk produce (1) an associated mechanical force utilizing a piezoelectric glide head and/or (2) an associated magnetic force utilizing a GMR read head; for (a) general use in surface characterization work and (b) for producing power by the presence or the absence of matter on a spinning disk.

1. Abstract
This invention uses the fact that the gravity force is as
strong as the electromagnetic forces; below one
millimeter distance, and gravity propagates at a slower
speed than electromagnetism. This Application is for a
Utility Patent on the use of a type device the inventor
characterizes as a “mass spin-valve” or “gravitational
rectifier” which uses gravitational frame dragging to
produce (1) an electric signal and/or (2) associated
mechanical force, for (A) general use in surface
characterization work and (B) power produced by the
presence or the absence of matter on a spinning disk.
Utility Patent Application US 13/595,424 Pending, 08/27/12
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2. Field of Invention
On Earth's surface, a mass of 1 kg exerts a force of
approximately 9.8 Newtons (N). 1 N is the force of
Earth's gravity on a mass of about 102 g = (1⁄9.81 kg) of
force [down] (or 1.0 kilogram-force; 1 kgf=9.80665 N by
definition). It is shown that the presence or the absence
of matter on a spinning disk’s surface creates gravity-
induction on the spinning disk that can be measured as a
mechanical force signal from piezoelectric Glide head
and also as an induced electrical signal on a GMR head.
It is shown that both bumps and pits on a spinning disk
produce a mechanical force that can be detected with a
piezoelectric crystal mounted on a head slider. It is
shown that an magneto-resistive (MR) element flying
over a spinning disk coated with a magnetic media can
be used to detect micro-fabricated pit and bump defects
down to the 1µm x 1µm in area and to less than 1µ”
height/depth or about 25.4 nm [25.4 x 10-9 meters].
Utility Patent Application US 13/595,424 Pending, 08/27/12
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3. Field of Invention-continued
It is shown that part of the MR modulation read back
signal corresponds to the switch in the magnetization
polarity of the media is produced by the edges of the
bumps and pits. The product of the time change between
the positive and negative magnetic transition modulation
pulses times the linear velocity scales to within 200nm of
the defects width along the circumference as measured
with an atomic-force microscope (AFM). It is shown that
the mass spin-valve signal (MS signal) signal is the
central peak offset voltage whose offset voltage is
dependent on the type of defect and its size. It is shown
that the MR magnetic modulation signal induced by a
micro-fabricated defect is dependent on the polarity of
DC erase on the MR media but the MR mass spin-valve
signal (or “MS” signal) is independent of the polarity of
DC erase.
Utility Patent Application US 13/595,424 Pending, 08/27/12
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4. Field of Invention-continued
Independent of the magnetic media it is shown that an
magneto-resistive (MR) element flying over a spinning
disk that the MR element experiences increasing MR
mass spin-valve signal MS signal with increasing defect
width along a radius perpendicular to the direction of disk
rotation. Pit defects exhibit an [up] going gravity-induced
force which can be converted to an electric MS signal
pulse due to increased MR element and disk spacing. It
is shown that the bump defects exhibit a [down] going
gravity-induced force which can be converted to an
electric MS signal pulse representing a decrease in the
MR element and disk spacing. For comparison
purposes, the expected equivalent normal gravity force
(in units of –nNewtons is calculated from the bump’s
volume as determined with the AFM and the density of
Tungsten (W) 19.3 g/cm3, as shown in Table 1.
Utility Patent Application US 13/595,424 Pending, 08/27/12
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5. MR mass MR mass Expected
AFM MR MR spin-valve spin-valve normal
Design Defect AFM Height Modulation Modulation Signal Signal Gravity Force
Width Type Width or Depth Pulse Delay x Maximum Minimum Bump Volume
(µm) (µm) (µin/ nm) Delay(µSec) Velocity(µm) Ampl(Vp) Ampl(Vp) x 19.3g/cm3
Anti-GForce GForce density of W
(nNewtons) (−nNewtons) (−nNewtons)
40 Bump 40.9 1.27/32.3 3.23 41.021 NA -2 -0.00010630
20 Bump 20.2 1.22/31 1.6 20.3 NA -0.805 -0.00002489
10 Bump 10.9 1.27/32.3 0.858 10.8966 NA -0.304 -0.00000755
6 Bump 6.56 1.22/31 0.518 6.5786 NA -0.185 -0.00000262
4 Bump 4.76 1.24/31.5 0.38 4.826 NA -0.14 -0.00000140
2 Bump 2.8 1.04/26.4 0.218 2.7686 NA -0.065 -0.00000041
1 Bump 2.4 1.05/26.7 0.19 2.413 NA -0.04 -0.00000030
40 Pit 42.2 1.7/43.2 3.31 42.037 0.378 NA NA
20 Pit 20.4 1.99/50.5 1.59 20.193 0.287 NA NA
10 Pit 10.3 2.02/51.3 0.814 10.3378 0.245 NA NA
6 Pit 6.28 1.92/48.8 0.498 6.3246 0.163 NA NA
4 Pit 4.25 1.59/40.4 0.34 4.318 0.141 NA NA
2 Pit 2.4 1.65/41.9 0.208 2.6416 0.102 NA NA
1 Pit 1.28 1.86/47.2 0.104 1.3208 0.055 NA NA
Table 1
Utility Patent Application US 13/595,424 Pending, 08/27/12
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6. Background of Related Art
Quality control for high density recording requires that
the computer’s hard disk surface be free of defects
larger than 1µm x 1µm in areal size or better. Current
methods for characterizing defects of this size are limited
by slow metrology techniques such as Atomic Force
Microscopy (AFM), the associated Magnetic Force
Microscopy (MFM), Magnetic Phase Microscope (MPM)
or faster techniques like Piezoelectric (PZT) Glide.
Another faster defect detection technique that uses spin
stands such as magnetic certification testers that detect
missing pulses at high frequency write and read rates
(i.e. Phase Metrics MG250 a type of hard disk certifier).
An atomic force microscope image from a 10µm x 10µm
area pit is shown in Figure 1
Utility Patent Application US 13/595,424 Pending, 08/27/12
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7. In Figure 1 a) is the AFM image. A magnetic force microscope image of a written
track from a typical hard disk is shown in Figure 1 b). An MR read back signal
from a magnetically erased disk and a certification missing pulse test reading for
the same 10µm x 10µm area pit are shown in Figures 1 c) and 1 d) respectively.
Utility Patent Application US 13/595,424 Pending, 08/27/12
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8. Fourteen defects were fabricated on a 2400 Oe 31.5mil 95mm MR disk using a Focused Ion
Beam (FIB). Seven bumps of ~1.25µin (~32nm) height were deposited, and seven pits
~2µin (~51nm) deep were etched, on a disk 50 mils (~1.27mm) apart on a radius, as shown
in Figure 2. See Table 1
1.8” 40x40 um
MS signal Calibration
Bump and Pit Disk
1.75” 20x20 um
1.6” 10x10 um
1.65” 6x6 um Bumps
1.6” 4x4 um
1.55” 2x2 um
1.5” 1x1 um
12.5
1.4” 40x40 um
1.45” 20x20 um 47.5
1.3” 10x10 um
Pits Critical Dimensions
1.35” 6x6 um
mm inch
12.5 0.49
47.5 1.87
1.2” 4x4 um
1.25” 2x2 um
1.2” 1x1 um
Utility Patent Application US 13/595,424 Pending, 08/27/12
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9. The MS signal of bump defects exhibited a negative polarity pulse as shown in Figure 3.
The 1.25µin 10µm x 10µm bump measured with an AFM produces a characteristic PZT
Glide signal [at 890 ips] of the downward force of the bump on the downward facing head
slider and a characteristic MR magnetic modulation signal plus MS signal of a bump.
Signal Characteristics from Reference 10µm x 10µm ~1.25 µin Bump Defect
AFM Microgaph
Non-contact PZT Glide Non-contact MS-valve signal
Utility Patent Application US 13/595,424 Pending, 08/27/12
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10. Figure 4 shows that for ~2µin 10µm x 10µm pit measured with an AFM produce
a PZT Glide signal [measured at 890 ips] and the characteristic MR magnetic
modulation signal plus MS signal of a pit.
Signal Characteristics from Reference 10µm x 10µm ~2 µin Pit Defect
AFM Micrograph
Non-contact PZT Glide Non-contact MS-valve signal
Utility Patent Application US 13/595,424 Pending, 08/27/12
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11. Figure 5 shows that 10µm x 10µm bump defect at a radius of 1.7 inches on a
disk spinning at a linear velocity of 500 inches per second exhibits two
electromagnetic signals due to electromagnetic induction created by the edges
of the bump defect following Maxwell’s right hand rule and also exhibits the
gravitational induction signal of 0.304 Volts
Utility Patent Application US 13/595,424 Pending, 08/27/12
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12. Figure 6 shows that 40µm x 40µm pit defect at a radius of 1.4 inches on a disk
spinning at a linear velocity of 500 inches per second exhibits two
electromagnetic signals due to electromagnetic induction created by the edges
of the pit defect and also exhibits the gravitational induction signal of 0.378 Volts
Utility Patent Application US 13/595,424 Pending, 08/27/12
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13. Background of Related Art -continued
In a metallic conductor, current is carried by the flow of
electrons. In semiconductors, current is often
schematized as being carried either by the flow of
electrons or by the flow of positively charged "holes" in
the electron structure of the material. This inventor
postulates that there exists an equivalent quantum
nature to gravity associated with the presence and
absence of matter on the spinning disk to the quantum
nature in electromagnetism in the semiconductor
junction [or a rectifier] as a type electromagnetic spin
valve device which is based on the spin of conduction
energy band electrons in the semiconductor crystal.
Utility Patent Application US 13/595,424 Pending, 08/27/12
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14. Figure 7 shows the gravitational induction equivalent as a gravitational rectifier in the
mass spin valve device; whereby the downward gravitational induction force [N type
donor gravitons] is produced by additional mass; equivalent to the electrons in the
semiconductor rectifier; and the upward gravitational induction force [P type acceptor
anti-gravitons] is produced by the absence of mass, equivalent to “holes” in the
semiconductor rectifier. Pit & Bump Volume v. Gforce Rectification
100
Bumps with Height ~+30ηm height Volume α Gf2
Bump Volume (µm3) = 6x(-Gf)2 - 7x(-Gf) - 0.4 80
R2 = 0.9997
60
Antigravitational Induction
Pit or Bump Volume(µm3)
40
20
0
-3.5 -2.5 -1.5 -0.5 0.5 1.5 2.5
-20 Pits with Depth ~-40ηm depth
Volume α Gf3
-40 Pit Volume (µm3) = -3000xGf3 +
Gravitational Induction -60 1000xGf2 - 200xGf + 8
R2 = 0.9979
-80
-100
Gforce (nNewton)
Utility Patent Application US 13/595,424 Pending, 08/27/12
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15. Figure 8 shows that a pit defect that is 10µm wide along a radius centered at 1.3925
inches and 100µm long along the circumference of the disk on a disk spinning at a linear
velocity of 500 inches per second exhibits an anti-gravitational induction signal that is
2.1µSec propagations delayed from the first electromagnetic signal due to
electromagnetic induction created by the edge of the pit defect.
Utility Patent Application US 13/595,424 Pending, 08/27/12
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16. Figure 9 shows that for pit defects there is a threshold of 2.1µSec propagation delay for
anti-gravitational induction frame dragging described by the relationship, Pit Delay (µSec)
α (Pit Width(µm))2 and also shows that for bump defects the threshold of propagation
delay for gravitational induction frame dragging was not yet sufficiently determined
Gravity-time dilation v. Width (µm)
6
Pit Delay (µSec) = -0.0004 x (Pit Width(µm)) 2 + 0.0574 x Pit Width(µm)
R2 = 0.995
5
Bump Delay (µSec) = 0.0568 x Bump Width(µm)
R2 = 0.9978
4
Time Delay (µSec)
Pit Delay (uSec)
Bump Delay (uSec)
Poly. (Pit Delay (uSec))
3
Linear (Bump Delay (uSec))
2
1
0
0 20 40 60 80 100 120
Defect Width (µm)
Utility Patent Application US 13/595,424 Pending, 08/27/12
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17. Figure 10 shows that the current piezoelectric glide defect detection utilized on
industrial hard disk certifiers is unable to detect pit type defects while certifier
missing pulse defect detection and correction algorithms are able to detect both
type defects (i.e., pits and bumps) fabricated on a MR disk using a FIB.
Utility Patent Application US 13/595,424 Pending, 08/27/12
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18. Figure 11 shows a high degree of correlation between in the detection of the (MR
magnetic modulation signal plus MS signal), labeled as MS signal, and the
certifier missing pulse defect detection and correction algorithms utilized by in
industrial hard disk certifiers.
Utility Patent Application US 13/595,424 Pending, 08/27/12
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19. Figure 12 shows the application of the patent for a scratch type defect on the
disk’s surface. The MR magnetic modulation signal plus MS signal are labeled as
non-contact MS-valve signal. The MR magnetic modulation signal exhibits
magnetic transition pulses only, with no MS signal present.
Mass Spin-valve Signal on Scratch Defect
Microscope Image ~2.5µm Width Non-contact MS-valve Signal
Utility Patent Application US 13/595,424 Pending, 08/27/12
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20. Figure 13 exhibits the results from a shallow pit type defect on the disk surface.
The read back signal exhibits MS signal only, with no MR magnetic modulation
signal present, but the characteristic polarity MS signal of a pit.
Mass Spin-valve Signal on Polishing Defect Pit
Microscope Image ~40µm x 30µm Non-contact MS-valve Signal
Utility Patent Application US 13/595,424 Pending, 08/27/12
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21. Figure 14 exhibits the results from a short bump type defect on the disk’s
surface. The read back signal exhibits MS signal only, with no MR magnetic
modulation signal present, but the characteristic MS signal of a bump .
Mass Spin-valve Signal on Bumps
Microscope Image ~40µm x 20µm Non-contact MS-valve Signal
Utility Patent Application US 13/595,424 Pending, 08/27/12
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22. Figure 15 shows that for some large defects a large thermal signal dominates the
MR modulation signal plus MS signal. The flash temperature rise (or drop)
nearby the MR sensor due to head disk contact (i.e., a head slap as pictured)
leads to a thermally induced signal from the MR read element. This is called a
“thermal asperity”.
Mass Spin-valve Signal on Head Slap
Microscope Image ~ 30µm x 10µm Contact MS-valve Signal
Utility Patent Application US 13/595,424 Pending, 08/27/12
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