DEFORMABLE INDUCTOR HAVING A LIQUID MAGNETIC CORE

• US 20180019049A1
• Filed: 07/13/2016
• Published: 01/18/2018
• Est. Priority Date: 07/13/2016
• Status: Active Grant

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: US Army Research Laboratory (Government of the United States of America)
• Inventors: Lazarus, Nathan S., Meyer, Christopher D.
• Granted Patent: US 10,553,342 B2
• Time in Patent Office: Days
• CPC Class Codes: H01F 1/44 of magnetic liquids, e.g. ferrofluids particles in a bonding agent H01F1/28, H01F1/36, H01F1/37
• CPC Class Codes: H01F 27/022 Encapsulation
• CPC Class Codes: H01F 27/24 Magnetic cores

Abstract

A deformable inductive device includes an elastomer material having at least one deformable electrode and a liquid magnetic core formed in the elastomer material and containing a magnetic liquid. Depending on the device'"'"'s configuration, the deformable element may be embedded in, attached to, or in close proximity with the liquid magnetic core. In some embodiments, the deformable inductive device may be configured as an inductor, solenoid, or transformer and the deformable electrode is at least partially embedded in the liquid magnetic core, for instance. In another embodiment, the deformable inductive device may be configured as part of a wireless power transfer system which includes a coil and a magnetic backplane having the liquid magnetic core with the coil being attached to or in close proximity to the magnetic backplane.

Claims

1. A deformable inductive device comprising:

an elastomer material having at least one deformable electrode; and

a liquid magnetic core formed in the elastomer material and containing a magnetic liquid.

2. The device of claim 1, wherein the deformable inductive device is an inductor, solenoid, or transformer and the deformable electrode is at least partially embedded in the elastomer material.

3. The device of claim 1, wherein the deformable inductive device is part of a wireless power transfer system comprising a coil and a magnetic backplane which includes the liquid magnetic core with the coil being attached to or in close proximity to the magnetic backplane.

4. The device of claim 1, wherein the elastomer material comprises a polymer or plastic material.

5. The device of claim 4, wherein the polymer comprises natural rubber or a silicone material.

6. The device of claim 1, wherein the magnetic liquid comprising a fluid having magnetic particles dispersed within.

7. The device of claim 6, wherein the fluid comprises mineral oil.

8. The device of claim 1, wherein the particles have a size on the order of about 10 nm.

9. The device of claim 1, wherein the magnetic liquid comprises a ferrofluid or magnetorheological fluid.

10. The device of claim 1, wherein the magnetic particles are formed of iron, nickel, cobalt and/or an alloy thereof, or carbonyl iron.

11. The device of claim 1, wherein the magnetic particles are generally spherical particles or platelets.

12. The device of claim 1, wherein the deformable electrode comprises at least one deformable conductive trace or at least one coil having one or more turns.

13. The device of claim 12, wherein the at least one deformable conductive trace is about 500 nm thick and 100 μ

m wide.

14. The device of claim 1, wherein the deformable electrode comprises at least one deformable channel containing a containing a liquid conductor.

15. The device of claim 14, wherein the liquid conductor comprises a liquid metal, flowable elastomer or polymer having conductive particles intermixed therein, or a fluid solution containing an ionic conductor or electrolyte.

16. The device of claim 15, wherein the liquid metal comprises Galinstan, eutectic gallium/indium, or mercury.

17. The device of claim 1, wherein the stretchable inductive device is configured to be deformable for at least ±

5% strain.

18. The device of claim 1, wherein the stretchable inductive device is configured to be deformable from about −

50% strain to about 100% strain.

20. A method for forming the deformable inductive device of claim 1, comprising the steps of:

preparing a mold, the mold including a removable element which will form the liquid magnetic core in the elastomer material;

casting elastomer material into the mold;

removing the removable element; and

filling the void in the elastomer material left by the removable element with the magnetic liquid.

19. A deformable inductive device comprising:

a liquid magnetic core comprising at least one channel containing a ferroliquid; and

a deformable electrode.