Semi-active isolators based on magnetorheological nanocomposites

• US 9,581,214 B2
• Filed: 06/23/2014
• Issued: 02/28/2017
• Est. Priority Date: 06/24/2013
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Sun, Lizhi, Sun, Hang, Li, Rui
• Primary Examiner(s): IRVIN, THOMAS W
• Application Number:
  US14/312,559
• Publication Number:
  US 20140376837A1
• Time in Patent Office: 981 Days
• US Class Current: 1/1
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: F16C 2210/06 magnetic fluids
• CPC Class Codes: F16C 32/0637 by a magnetic field, e.g. ferrofluid bearings
• CPC Class Codes: F16C 33/1035 by a magnetic field acting on a magnetic liquid
• CPC Class Codes: F16C 33/6644 by a magnetic field acting on a magnetic liquid
• CPC Class Codes: F16F 1/361 comprising magneto-rheological elastomers [MR], magneto-rheological fluid dampers F16F9/535
• CPC Class Codes: H01F 1/447 characterised by magnetoviscosity, e.g. magnetorheological, magnetothixotropic, magnetodilatant liquids electrorheological fluids C10M171/001

Abstract

Systems, devices, uses and methods relating to magnetorhological materials including carbon nanotubes, such as single-walled and multi-walled carbon nanotubes, are disclosed. Uses of magnetorheological materials such as in motion damping/vibration isolation are also disclosed.

Claims

1. A magnetorheological material (MRM) comprising:

a polymeric matrix;

ferromagnetic particles embedded in the polymeric matrix; and

carbon nanotubes embedded in the polymeric matrix;

wherein the magnetorheological material is a solid.

2. The MRM of claim 1, wherein the polymeric matrix comprises an elastomer.

3. The MRM of claim 1, wherein the ferromagnetic particles comprise iron.

4. The MRM of claim 1, wherein at least a portion of the ferromagnetic particles are ordered into chains.

5. The MRM of claim 1, wherein at least a portion of the ferromagnetic particles are associated with at least a portion of the carbon nanotubes.

6. The MRM of claim 1, wherein at least a portion of the ferromagnetic particles and the carbon nanotubes form a layered arrangement.

7. The MRM of claim 1, wherein the carbon nanotubes are multiwalled nanotubes (MWNT).

8. The MRM of claim 2, wherein the elastomer comprises a silicone material.

9. A motion damper comprising:

a base;

a bearing comprising a magnetorheological material comprising carbon nanotubes and ferromagnetic particles embedded in a polymeric matrix, the bearing having a first end attached to said base;

a coil coupled to the base and capable of controllably submitting the bearing to a magnetic field, wherein the magnetic field changes at least one viscoelastic property of a component of the bearing; and

an actuation plate attached to a second end of the bearing.

10. The motion damper of claim 9, wherein:

the base comprises a base plate.

11. The motion damper of claim 10, wherein the bearing comprises at least one plate of laminated steel disposed parallel to the base plate;

the at least one plate of laminated steel being coated with the magnetorheological material comprising carbon nanotubes.

12. The motion damper of claim 11, wherein said coil comprises a coil wound around a core attached to the base plate and positioned at a central portion of the bearing.

13. The motion damper of claim 11, wherein the damper element comprises at least two plates of steel spaced apart from one another and separated by the magnetorheological material comprising carbon nanotubes.

14. A motion damper comprising:

a bearing comprising a magnetorheological material comprising carbon nanotubes and ferromagnetic particles embedded in a polymeric matrix;

a first attachment point;

a second attachment point; and

a coil magnetically coupled to the bearing and capable of controllably submitting the bearing to a magnetic field, wherein the first and second attachment points are mechanically attached directly or indirectly to different portions of the bearing.

15. The motion damper of claim 14, wherein the bearing further comprises at least one rigid inclusion body.

16. The motion damper of claim 15, wherein the rigid inclusion body is magnetic reactive.

17. The motion damper of claim 15, wherein the rigid inclusion body is a plate.

18. The motion damper of claim 17, wherein the rigid inclusion body is a steel plate.

19. The motion damper of claim 18, wherein the at least one rigid inclusion body comprises a plurality of steel plates.

20. The motion damper of claim 19, wherein the plurality of steel plates form a laminated structure with the magnetorheological material comprising nanotubes.