# US 7,200,956 B1 · Magnetic fluid cushioning device for a footwear or shoe

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,200,956 B1
- Document ID: US7200956B1
- Status: Granted
- Kind: B1
- Application number: 10/624,519
- Filed: 2003-07-23
- Granted: 2007-04-10
- Earliest claimed: 2003-07-23
- Assignees: Materials Modification, Inc.
- Inventors: Sanjay Kotha; Tirumalai S. Sudarshan
- Web page: https://patentgrep.com/patent/US7200956B1

## CPC

- A43B 13/189: {filled with a non-compressible fluid, e.g. gel, water}
- A43B 1/0054: {provided with magnets, magnetic parts or magnetic substances}
- A43B 3/44: with sensors, e.g. for detecting contact or position
- A43B 17/026: {filled with a non-compressible fluid, e.g. gel, water}
- A43B: CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR

## Abstract

A cushioning device for a footwear or shoe includes a chamber with a magnetically responsive fluid therein for absorbing and/or dampening vibrations and/or shocks. A magnetic member, such as an electromagnet, is provided for applying a magnetic field to the magnetic fluid to thereby vary the viscosity thereof.

## Claims

### Claim 1

A cushioning device for a footwear, comprising:
a) a chamber including a magnetically responsive fluid;
b) said fluid comprising core particles of a magnetic material;
c) said core particles comprising first and second successive coatings;
d) one of said first and second coatings comprising a coating of at least one member selected from the group consisting of a ceramic material, a metallic material, and a combination thereof; and
e) a magnetic member for applying a magnetic field to said fluid thereby varying the viscosity thereof.

### Claim 2 (depends on 1)

The cushioning device of claim 1, wherein:
a) the viscosity of said fluid is greater than the viscosity of at least one member selected from the group consisting of water, glycerine, hydraulic oil, mineral oil, and a combination thereof.

### Claim 3 (depends on 1)

The cushioning device of claim 1, further comprising:
a) a weight sensor for determining the weight of a user of a footwear.

### Claim 4 (depends on 1)

The cushioning device of claim 1, further comprising:
a) a movement sensor for determining the movement of a footwear.

### Claim 5 (depends on 3)

The cushioning device of claim 3, further comprising:
a) a control unit for receiving information from said weight sensor and relaying a signal to said magnetic member to apply a magnetic field.

### Claim 6 (depends on 1)

The cushioning device of claim 1, wherein:
a) a plurality of said core particles are attracted to form a magnetically connected structure when a magnetic field is applied to said fluid.

### Claim 7 (depends on 6)

The cushioning device of claim 6, wherein:
a) said structure comprises generally rectilinear or bent configuration.

### Claim 8 (depends on 1)

The cushioning device of claim 1, wherein:
a) said core particles have an average diameter of about 1 nm to 100 μm.

### Claim 9 (depends on 8)

The cushioning device of claim 8, wherein:
a) said core particles have an average diameter of about 1 nm to 10 μm.

### Claim 10 (depends on 9)

The cushioning device of claim 9, wherein:
a) said core particles have an average diameter of about 10 nm to 5 μm.

### Claim 11 (depends on 1)

The cushioning device of claim 1, wherein:
a) said magnetic material comprises at least one member selected from the group consisting of iron, iron oxide, cobalt, cobalt oxide, nickel, nickel oxide, an alloy, and a combination thereof.

### Claim 12 (depends on 1)

The cushioning device of claim 1, wherein:
a) the other of said first and second coatings comprises a coating of a surfactant.

### Claim 13 (depends on 12)

The cushioning device of claim 12, wherein:
a) said surfactant comprises at least one member selected from the group consisting of lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof.

### Claim 14 (depends on 1)

The cushioning device of claim 1, wherein:
a) the member is selected from the group consisting of silica, gold, silver, platinum, steel, cobalt, carbon, dextran, and a combination thereof.

### Claim 15 (depends on 1)

The cushioning device of claim 1, wherein:
a) said first coating comprises a coating of a surfactant; and
b) said second coating comprises a coating of the member.

### Claim 16 (depends on 15)

The cushioning device of claim 15, wherein:
a) said surfactant comprises at least one member selected from the group consisting of lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof.

### Claim 17 (depends on 16)

The cushioning device of claim 16, wherein:
a) said second coating comprises at least one member selected from the group consisting of silica, gold, silver, platinum, steel, cobalt, carbon, dextran, and a combination thereof.

### Claim 18 (depends on 8)

The cushioning device of claim 8, wherein:
a) the other of said first and second coatings comprises a coating of a surfactant; and
b) said core particles are dispersed in a carrier fluid.

### Claim 19 (depends on 18)

The cushioning device of claim 18, wherein:
a) said carrier fluid comprises a water-based or an oil-based carrier fluid.

### Claim 20 (depends on 18)

The cushioning device of claim 18, wherein:
a) said carrier fluid comprises at least one member selected from the group consisting of water, hydraulic oil, mineral oil, silicone oil, biodegradable oil, and a combination thereof.

### Claim 21 (depends on 18)

The cushioning device of claim 18, wherein:
a) said fluid comprises about 1–95% of said core particles.

### Claim 22 (depends on 8)

The cushioning device of claim 8, wherein:
a) said core particles comprise at least one general shape selected from the group consisting of spherical, needle-shaped, cubic, irregular, cylindrical, diamond, oval, and a combination thereof.

### Claim 23

A sole for a footwear, comprising:
a) a chamber including a magnetically responsive fluid;
b) said fluid comprising core particles of a magnetic material;
c) said core particles comprising first and second successive coatings;
d) one of said first and second coatings comprising a coating of at least one member selected from the group consisting of a ceramic material, a metallic material, and a combination thereof;
e) a magnetic member for applying a magnetic field to said fluid thereby varying the viscosity thereof; and
f) a control unit for relaying a signal to said magnetic member to apply a magnetic field.

### Claim 24 (depends on 23)

The sole of claim 23, wherein:
a) the viscosity of said fluid is greater that the viscosity of at least one member selected from the group consisting of water, glycerine, hydraulic oil, mineral oil, and a combination thereof.

### Claim 25 (depends on 23)

The sole of claim 23, further comprising:
a) a weight sensor for determining the weight of a user of a footwear.

### Claim 26 (depends on 23)

The sole of claim 23, further comprising:
a) a movement sensor for determining the movement of a footwear.

### Claim 27 (depends on 25)

The sole of claim 25, wherein:
a) said control unit receives information from said weight sensor for relaying a signal to said magnetic member to apply a magnetic field.

### Claim 28 (depends on 27)

The sole of claim 27, wherein:
a) the strength of a magnetic field applied by said magnetic member is proportional to the weight of a user.

### Claim 29 (depends on 23)

The sole of claim 23, wherein:
a) a plurality of said core particles form a magnetically connected structure when a magnetic field is applied to said fluid.

### Claim 30 (depends on 29)

The sole of claim 29, wherein:
a) said structure comprises a generally rectilinear or bent configuration.

### Claim 31 (depends on 30)

The sole of claim 30, wherein:
a) said structure is oriented in a generally vertical direction.

### Claim 32 (depends on 23)

The sole of claim 23, wherein:
a) the sole comprises toe and heel portions each including one said chamber.

### Claim 33 (depends on 32)

The sole of claim 32, wherein:
a) each of said toe and heel portions includes one said magnetic member.

### Claim 34 (depends on 33)

The sole of claim 33, wherein:
a) the strengths of the magnetic fields applied by the magnetic members of said toe and heel portions may be substantially the same or different.

### Claim 35 (depends on 33)

The sole of claim 33, wherein:
a) the magnetic members of said toe and heel portions apply magnetic fields substantially simultaneously or at different times.

### Claim 36 (depends on 23)

The sole of claim 23, wherein:
a) said core particles have an average diameter of about 1 nm to 100 μm.

### Claim 37 (depends on 36)

The sole of claim 36, wherein:
a) said core particles have an average diameter of about 1 nm to 10 μm.

### Claim 38 (depends on 37)

The sole of claim 37, wherein:
a) said core particles have an average diameter of about 10 nm to 5 μm.

### Claim 39 (depends on 23)

The sole of claim 23, wherein:
a) said magnetic material comprises at least one member selected from the group consisting of iron, iron oxide, cobalt, cobalt oxide, nickel, nickel oxide, an alloy, and a combination thereof.

### Claim 40 (depends on 23)

The sole of claim 23, wherein:
a) the other of said first and second coatings comprises a coating of a surfactant.

### Claim 41 (depends on 40)

The sole of claim 40, wherein:
a) said surfactant comprises at least one member selected from the group consisting of lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof.

### Claim 42 (depends on 23)

The sole of claim 23, wherein:
a) the member is selected from the group consisting of silica, gold, silver, platinum, steel, cobalt, carbon, dextran, and a combination thereof.

### Claim 43 (depends on 23)

The sole of claim 23, wherein:
a) said first coating comprises a coating of a surfactant; and
b) said second coating comprises a coating of the member.

### Claim 44 (depends on 43)

The sole of claim 43, wherein:
a) said surfactant comprises at least one member selected from the group consisting of lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof.

### Claim 45 (depends on 44)

The sole of claim 44, wherein:
a) said second coating comprises at least one member selected from the group consisting of silica, gold, silver, platinum, steel, cobalt, carbon, dextran, and a combination thereof.

### Claim 46 (depends on 36)

The sole of claim 36, wherein:
a) the other of said first and second coatings comprises a coating of a surfactant; and
b) said core particles are dispersed in a carrier fluid.

### Claim 47 (depends on 46)

The sole of claim 46, wherein:
a) said carrier fluid comprises a water-based or an oil-based carrier fluid.

### Claim 48 (depends on 46)

The sole of claim 46, wherein:
a) said carrier fluid comprises at least one member selected from the group consisting of water, hydraulic oil, mineral oil, silicone oil, biodegradable oil, and a combination thereof.

### Claim 49 (depends on 46)

The sole of claim 46, wherein:
a) said fluid comprises about 1–95% of said core particles.

### Claim 50 (depends on 36)

The sole of claim 36, wherein:
a) said core particles comprise at least one general shape selected from the group consisting of spherical, needle-shaped, cubic, irregular, cylindrical, diamond, oval, and a combination thereof.

### Claim 51

A sole for a footwear, comprising:
a) a chamber including a magnetically responsive fluid;
b) said fluid comprising core particles of a magnetic material;
c) said core particles comprising first and second successive coatings;
d) one of said first and second coatings comprising a coating of at least one member selected from the group consisting of a ceramic material, a metallic material, and a combination thereof;
e) an electromagnet for applying a magnetic field to said fluid thereby varying the viscosity thereof;
f) a movement sensor for determining the movement of a footwear;
g) a weight sensor for determining the weight of a user of a footwear; and
h) a control unit for receiving information from one of said movement and weight sensors and relaying a signal to said electromagnet for applying a magnetic field.

### Claim 52 (depends on 51)

The sole of claim 51, wherein:
a) the viscosity of said fluid is greater than the viscosity of at least one member selected from the group consisting of water, glycerine, hydraulic oil, mineral oil, and a combination thereof.

### Claim 53 (depends on 51)

The sole of claim 51, wherein:
a) the strength of a magnetic field applied by said magnetic member is proportional to the weight of a user.

### Claim 54 (depends on 51)

The sole of claim 51, wherein:
a) a plurality of said core particles form a magnetically connected structure when a magnetic field is applied to said fluid.

### Claim 55 (depends on 54)

The sole of claim 54, wherein:
a) said structure comprises a generally rectilinear or bent configuration.

### Claim 56 (depends on 55)

The sole of claim 55, wherein:
a) said structure is oriented in a generally vertical direction.

### Claim 57 (depends on 51)

The sole of claim 51, wherein:
a) the sole comprises toe and heel portions each including one said chamber.

### Claim 58 (depends on 57)

The sole of claim 57, wherein:
a) each of said toe and heel portions includes one said magnetic member.

### Claim 59 (depends on 58)

The sole of claim 58, wherein:
a) the strengths of the magnetic fields applied by the magnetic members of said toe and heel portions may be substantially the same or different.

### Claim 60 (depends on 58)

The sole of claim 58, wherein:
a) the magnetic members of said toe and heel portions apply magnetic fields substantially simultaneously or at different times.

### Claim 61 (depends on 51)

The sole of claim 51, wherein:
a) said core particles have an average diameter of about 1 nm to 100 μm.

### Claim 62 (depends on 61)

The sole of claim 61, wherein:
a) said core particles have an average diameter of about 1 nm to 10 μm.

### Claim 63 (depends on 62)

The sole of claim 62, wherein:
a) said core particles have an average diameter of about 10 nm to 5 μm.

### Claim 64 (depends on 51)

The sole of claim 51, wherein:
a) said magnetic material comprises at least one member selected from the group consisting of iron, iron oxide, cobalt, cobalt oxide, nickel, nickel oxide, an alloy, and a combination thereof.

### Claim 65 (depends on 51)

The sole of claim 51, wherein:
a) the other of said first and second coatings comprises a coating of a surfactant.

### Claim 66 (depends on 65)

The sole of claim 65, wherein:
a) said surfactant comprises at least one member selected from the group consisting of lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof.

### Claim 67 (depends on 59)

The sole of claim 59, wherein:
a) the member is selected from the group consisting of silica, gold, silver, platinum, steel, cobalt, carbon, polystyrene, dextran, and a combination thereof.

### Claim 68 (depends on 51)

The sole of claim 51, wherein:
a) said first coating comprises a coating of a surfactant; and
b) said second coating comprises a coating of the member.

### Claim 69 (depends on 68)

The sole of claim 68, wherein:
a) said surfactant comprises at least one member selected from the group consisting of lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof.

### Claim 70 (depends on 69)

The sole of claim 69, wherein:
a) said second coating comprises at least one member selected from the group consisting of silica, gold, silver, platinum, steel, cobalt, carbon, dextran, and a combination thereof.

### Claim 71 (depends on 61)

The sole of claim 61, wherein:
a) the other of said first and second coatings comprises a coating of a surfactant; and
b) said core particles are dispersed in a carrier fluid.

### Claim 72 (depends on 71)

The sole of claim 71, wherein:
a) said carrier fluid comprises a water-based or an oil-based carrier fluid.

### Claim 73 (depends on 71)

The sole of claim 71, wherein:
a) said carrier fluid comprises at least one member selected from the group consisting of water, hydraulic oil, mineral oil, silicone oil, biodegradable oil, and a combination thereof.

### Claim 74 (depends on 71)

The sole of claim 71, wherein:
a) said fluid comprises about 1–95% of said core particles.

### Claim 75 (depends on 61)

The sole of claim 61, wherein:
a) said core particles comprise at least one general shape selected from the group consisting of spherical, needle-shaped, cubic, irregular, cylindrical, diamond, oval, and a combination thereof.

### Claim 76 (depends on 51)

The sole of claim 51, wherein:
a) said control unit receives information from said movement sensor for relaying a signal to said electromagnet to apply a magnetic field.

### Claim 77 (depends on 76)

The sole of claim 76, wherein:
a) the strength of a magnetic field applied by said electromagnet depends on a type of movement detected by said movement sensor.

### Claim 78 (depends on 77)

The sole of claim 77, wherein:
a) the type of movement is selected from the group consisting of walking, brisk walking, jogging, running, jumping, stepping, and skipping.

### Claim 79 (depends on 51)

The sole of claim 51, wherein:
a) said control unit receives information from both of said movement and weight sensors.

### Claim 80 (depends on 51)

The sole of claim 51, wherein:
a) the strength of a magnetic field applied by said electromagnet depends on a type of movement detected by said movement sensor.

### Claim 81 (depends on 80)

The sole of claim 80, wherein:
a) the type of movement is selected from the group consisting of walking, brisk walking, jogging, running, jumping, stepping, and skipping.

### Claim 82 (depends on 8)

The cushioning device of claim 8, wherein:
a) said core particles comprise a plurality of groups of particles having different average diameters.

### Claim 83 (depends on 36)

The sole of claim 36, wherein:
a) said core particles comprise a plurality of groups of particles having different average diameters.

### Claim 84 (depends on 61)

The sole of claim 61, wherein:
a) said core particles comprise a plurality of groups of particles having different average diameters.

### Claim 85

A method of varying the shock absorbing capacity of a footwear cushioning device, comprising:
a) providing a cushioning device, comprising:
i. a chamber including a magnetically responsive fluid;
ii the fluid comprising core particles of a magnetic material;
iii) the particles comprising first and second successive coatings;
iv) one of said first and second coatings comprising a coating of at least one member selected from the group consisting of a ceramic material, a metallic material, and a combination thereof; and
v) a magnetic member for applying a magnetic field to the fluid;
b) applying a magnetic field to the fluid based on an input to thereby vary the viscosity of the fluid; and
c) whereby a change in viscosity of the magnetic fluid changes the shock absorbing capacity of the cushioning device.

### Claim 86 (depends on 85)

The method of claim 85, wherein:
the input in step b) comprises weight data for a user received from a weight sensor.

### Claim 87 (depends on 85)

The method of claim 85, wherein:
the input in step b) comprises movement data for a footwear received from a movement sensor.