Magnetorheological fluid cell systems and methods

Patent metadata

Field	Value
Publication number	US-12422016-B2
Application number	US-202217900070-A
Country	US
Kind code	B2
Filing date	Aug 31, 2022
Priority date	Aug 31, 2021
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

A magnetorheological apparatus includes a flexible body formed of an elastomer material, a plurality of cell cavities defined by the flexible body, a magnetorheological (MR) fluid disposed within each cell cavity of the plurality of cell cavities, and a magnetic field inductor positioned adjacent to at least one of the cell cavities. Each cell cavity of the plurality of cell cavities is fluidly encapsulated within the flexible body. The magnetic field inductor is selectively operable to vary a magnetic field, and the MR fluid within the at least one cell cavity is configured to vary a stiffness of the at least one cell cavity in response to the magnetic field.

First claim

We claim:

1. A magnetorheological joint system, comprising:
(a) a first joint element;
(b) a magnetorheological apparatus coupled with the first joint element, including:
(i) a flexible body formed of a material including an elastomer;
(ii) a plurality of cell cavities defined by the flexible body, wherein each cell cavity of the plurality of cell cavities is fluidly encapsulated within the flexible body;
(iii) a magnetorheological (MR) fluid disposed within each cell cavity of the plurality of cell cavities; and
(iv) a magnetic field inductor positioned adjacent to at least one of the cell cavities, wherein the magnetic field inductor is selectively operable to vary a magnetic field, wherein the MR fluid within the at least one cell cavity is configured to vary a stiffness of the at least one cell cavity in response to the magnetic field, and

(c) a second joint element configured to movably contact the magnetorheological apparatus such that the magnetorheological apparatus provides multiple degrees of freedom of movement between the first joint element and the second joint element with variable stiffness.

2. The magnetorheological joint system of claim 1 , comprising a power source selectively operable to provide a power signal to the magnetic field inductor to vary the magnetic field.

3. The magnetorheological joint system of claim 1 , wherein the elastomer includes silicone rubber.

4. The magnetorheological joint system of claim 1 , wherein the magnetic field inductor includes an electromagnet.

5. The magnetorheological joint system of claim 1 , comprising a plurality of magnetic field inductors each positioned adjacent to one cell cavity of the plurality of cell cavities, wherein each magnetic field inductor is individually operable to provide an individualized magnetic field to vary the stiffness of each respective cell cavity in response to the individualized magnetic field.

6. The magnetorheological joint system of claim 1 , wherein each cell cavity defines a hexagonal shape.

7. The magnetorheological joint system of claim 6 , wherein each hexagonal cell cavity includes a plurality of sides, wherein at least one side of each cell cavity abuts another side of another cell cavity to form a shared wall, wherein shared wall thickness is 1.3 millimeters.

8. A magnetorheological apparatus, comprising:
(a) a flexible body formed including an elastomer material, wherein the flexible body includes a first portion defining a plurality of hexagonal cell cavities each having an open end and a second portion shaped to close the open end of each of the plurality of cell cavities, wherein each cell cavity of the plurality of cell cavities is fluidly encapsulated within the flexible body upon being closed using the second portion; and
(b) a magnetorheological (MR) fluid disposed within each cell cavity of the plurality of cell cavities, and
wherein a first side of the flexible body is configured to movably couple with a first articulated component and a second side of the flexible body is configured to movably couple with a second articulated component, wherein the magnetorheological apparatus is selectively operable to act as a joint having variable stiffness between the first articulated component and the second articulated component.

9. The magnetorheological apparatus of claim 8 , wherein the elastomer includes silicone rubber.

10. The magnetorheological apparatus of claim 8 , comprising a magnetic field inductor positioned adjacent to at least one of the cell cavities, wherein the magnetic field inductor is selectively operable to vary a magnetic field, wherein the MR fluid within the at least one cell cavity is configured to vary a stiffness of the at least one cell cavity in response to the magnetic field.

11. The magnetorheological apparatus of claim 8 , comprising a plurality of magnetic field inductors each positioned adjacent to one cell cavity of the plurality of cell cavities, wherein each magnetic field inductor is individually operable to provide an individualized magnetic field to vary a stiffness of each respective cell cavity in response to the individualized magnetic field.

12. A method of manufacturing a magnetorheological apparatus, wherein the magnetorheological apparatus includes a flexible body, a plurality of cell cavities defined by the flexible body, and a magnetorheological (MR) fluid disposed within each cell cavity, the method comprising:
(a) providing a first articulated component and a second articulated component;
(b) molding the flexible body;
(c) casting the flexible body using an elastomeric material; and
(d) inserting the MR fluid into each cell cavity defined by the flexible body, wherein inserting the MR fluid includes puncturing the flexible body with a first syringe and injecting the magnetorheological fluid, and puncturing the flexible body with a second syringe, using the second syringe to simultaneously extract air from the cell cavity; and
(e) forming an articulable joint between the first articulated component and the second articulated component, including: (i) movably coupling a first side of the flexible body with the first articulated component; and (ii) movably coupling a second side of the flexible body with the second articulated component, wherein the magnetorheological apparatus comprising the flexible body is selectively operable to act as a joint having variable stiffness between the first articulated component and the second articulated component.

13. The method of claim 12 , wherein molding the flexible body includes separately molding a first portion and a second portion, wherein casting the flexible body includes separately casting the first portion and the second portion, the method comprising: affixing the first portion to the second portion, wherein each cell cavity of the plurality of cell cavities is fluidly encapsulated within the flexible body upon affixing the first portion to the second portion.

14. The method of claim 12 , wherein the flexible body includes silicone rubber.

15. The method of claim 12 , wherein molding the flexible body includes forming the plurality of cell cavities each having a hexagonal shape.

16. The method of claim 15 , wherein each hexagonal cell cavity includes a plurality of sides, wherein at least one side of each cell cavity abuts another side of another cell cavity to form a shared wall, wherein shared wall thickness is 1.3 millimeters.

17. The method of claim 12 , comprising:
upon inserting the MR fluid into each cell cavity defined by the flexible body, sealing a hole created by the syringe through the flexible body.

18. The method of claim 12 , comprising:
positioning a magnetic field inductor adjacent to at least one of the cell cavities.

19. The method of claim 18 , comprising:
(a) coupling a power source to the magnetic field inductor; and
(b) configuring the magnetic field inductor to receive a power signal and, in response to the power signal, vary a magnetic field to adjust a stiffness of at least one cell cavity.

Assignees

• Purdue Research Foundation

Inventors

• Rastgaar Mo
• Torres Rivera Gabriel Andrés

Classifications

• F16F2224/045

  magnetorheological · CPC title

• F16F2230/36

  Holes, slots or the like · CPC title

• F16F2234/00

  Shape · CPC title

• F16F2224/025

  Elastomers · CPC title

• A61F2002/6854

  for locking or unlocking a joint · CPC title