IP Library Granted Patent US 11,685,271
Granted Patent B2
US 11,685,271 · App. 17/462,126 · Granted Jun 27, 2023

Wireless non-radiative energy transfer

Inventors: John D. Joannopoulos (Belmont, MA); Aristeidis Karalis (Boston, MA); Marin Soljacic (Belmont, MA)
Assignee: Massachusetts Institute of Technology
B60L53/126H01F38/14H01Q9/04H02J50/12H02J50/40Y02T10/70Y02T10/7072Y02T90/12Y02T90/14
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Quick Facts
Patent No.
US 11,685,271
App. No.
17/462,126
Granted
Jun 27, 2023
Kind
B2
Abstract

Described herein are embodiments of a source high-Q resonator, optionally coupled to an energy source, a second high-Q resonator, optionally coupled to an energy drain that may be located a distance from the source resonator. A third high-Q resonator, optionally coupled to an energy drain that may be located a distance from the source resonator. The source resonator and at least one of the second resonator and third resonator may be coupled to transfer electromagnetic energy from said source resonator to said at least one of the second resonator and third resonator.

Claims (31)

1. A method of transferring electromagnetic energy comprising:

providing a first resonator structure receiving energy from an external power supply, said first resonator structure has a first Q-factor Q 1 ,

providing a second resonator structure being positioned distal from said first resonator structure and supplying useful working power to an external load, said second resonator structure has a second Q-factor Q 2 ,

transferring non-radiative energy between the first resonator structure and the second resonator structure through coupling of their resonant-field evanescent tails,

wherein the resonator structures use resonant modes of high Q=ω/(2Γ) for low intrinsic-loss rates Γ 1,2 and with evanescent tails significantly longer than the characteristic sizes L 1 and L 2 of the two resonators structures for the non-radiative energy transfer,

characterized in that Q 1 >100, and Q 2 >100, and

κ/sqrt(Γ 1 *Γ 2 )>2, where κ is the coupling rate for the non-radiative energy transfer.

2. The method of claim 1 , wherein Q 1 >200, and Q 2 >200.

3. The method of claim 1 , wherein Q 1 >500, and Q 2 >500.

4. The method of claim 1 , wherein the resonant modes cause a strong coupling rate |κ 12,21 | over large distances D between the resonator structures.

5. The method of claim 4 , wherein κ/sqrt(Γ 1 *Γ 2 )>5 and D/L 2 >1.

6. An electromagnetic energy transfer device comprising:

a first resonator structure receiving energy from an external power supply, said first resonator structure has a first Q-factor Q 1 and is for use together with

a second resonator structure positioned distal from said first resonator structure and supplying useful working power to an external load, said second resonator structure has a second Q-factor Q 2 ,

wherein non-radiative energy transfer between said first resonator structure and said second resonator structure is mediated through coupling of their resonant-field evanescent tails,

wherein the resonator structures use resonant modes of high Q=ω/(2Γ) for low intrinsic-loss rates Γ 1,2 ,

characterized in that Q 1 >100, and Q 2 >100, and

κ/sqrt(Γ 1 *Γ 2 )>2, where κ is the coupling rate for the non-radiative energy transfer.

7. The device of claim 6 , wherein Q 1 >200, and Q 2 >200.

8. The device of claim 6 , wherein Q 1 >500, and Q 2 >500.

9. The device of claim 6 , wherein the resonant modes enable high energy transfer efficiency over large distances D between the resonator structures.

10. The device of claim 9 , wherein κ/sqrt(Γ 1 *Γ 2 )>5 and D/L 2 >1.

11. The energy transfer device of claim 6 , wherein said first resonator structure comprises a capacitively-loaded conducting-wire loop having a characteristic size L 1 , where the characteristic size L 1 is the radius of the loop.

12. The method of claim 1 , wherein the second resonator structure is part of a mobile wireless receiver comprising the external load.

13. The method of claim 12 , wherein the mobile wireless receiver is any of a robot, a vehicle, or a computer.

14. The device of claim 6 , wherein the second resonator structure is part of a mobile wireless receiver comprising the external load.

15. The device of claim 14 , wherein the mobile wireless receiver is any of a robot, a vehicle, or a computer.

16. The method of claim 1 , further comprising applying a feedback mechanism to match the resonance of the first and second resonator structures.

17. The device of claim 6 , further comprising a feedback mechanism to match the resonance of the first and second resonator structures.

18. The device of claim 6 , further comprising the external power supply from which the first resonator structure receives energy.

19. The energy transfer device of claim 7 , wherein said second resonator structure comprises a capacitively-loaded conducting-wire loop having a characteristic size L 2 , where the characteristic size L 2 is the radius of the loop.

Assignments (3)
CONFIRMATORY LICENSE Recorded Apr 1, 2025
From: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
To: NATIONAL SCIENCE FOUNDATION
Reel/Frame 070700/0623 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 1, 2021
From: JOANNOPOULOS, JOHN D.; KARALIS, ARISTEIDIS; SOLJACIC, MARIN
To: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
Reel/Frame 057349/0951 →
LICENSE Recorded Sep 1, 2021
From: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
To: WITRICITY CORPORATION
Reel/Frame 057394/0852 →
Continuity (11)
Continuation 16851598 · Apr 17, 2020
Continuation 16184354 · Nov 8, 2018
Continuation 15793198 · Oct 25, 2017
Continuation 15083726 · Mar 29, 2016
Continuation 14629709 · Feb 24, 2015
Continuation 14302662 · Jun 12, 2014
Continuation 12639963 · Dec 16, 2009
Continuation 12553957 · Sep 3, 2009
Continuation 11481077 · Jul 5, 2006
Provisional Application 60698442 · Jul 12, 2005
Related Publication 20220123594A1 · Apr 21, 2022