IP Library › Granted Patent US 12,571,948
Granted Patent B2
US 12,571,948 · App. 18/049,857 · Granted Mar 10, 2026

Thermally adaptive coatings for efficient heating and cooling applications

Inventors: Joseph A. Miragliotta (Ellicott City, MD); David B. Shrekenhamer (Bethesda, MD); Andrew C. Strikwerda (Cambridge, MA); Gabriella M. Hunt (Baltimore, MD)
Assignee: The Johns Hopkins University
G02B5/208
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Quick Facts
Patent No.
US 12,571,948
App. No.
18/049,857
Granted
Mar 10, 2026
Kind
B2
Abstract

A composite and an adaptive coating are provided. The composite includes a first layer, a second layer disposed on the first layer, and a third layer disposed on the second layer. The third layer constitutes a phase change material characterized by a transition temperature. The phase change material includes a dopant. The adaptive coating includes a visible light filter and the phase change material. When a temperature of the phase change material exceeds a threshold temperature, the adaptive coating is configured to radiate light in the infrared spectrum. When the temperature of the phase change material is less than the threshold temperature, the adaptive coating is configured not to radiate light in the infrared spectrum.

Claims (57)

1 . A composite comprising:

a first layer;

a second layer disposed on the first layer; and

a third layer disposed on the second layer, wherein:

the third layer constitutes a phase change material characterized by a transition temperature,

the phase change material includes a dopant, and

the second layer comprises a material that is lattice-matched to a lattice of the first layer.

2 . The composite of claim 1 , wherein:

a thickness of the third layer is less than or equal to 100 nm.

3 . The composite of claim 1 , wherein:

the transition temperature of the phase change material is greater than or equal to 0° C. and less than or equal to 100° C.

4 . The composite of claim 1 , wherein:

the phase change material undergoes a reversible metal to insulator (MI) transition.

5 . The composite of claim 1 , wherein:

the phase change material is VO 2 .

6 . The composite of claim 5 , wherein:

the dopant is W.

7 . The composite of claim 1 , wherein:

a concentration of the dopant in the phase change material is expressed as A x B 1-x , where A is a dopant atom, B is an atom of the phase change material, and X is a concentration of the dopant, and

X is less than or equal to 0.02.

8 . The composite of claim 1 , wherein:

the phase change material has a chemical formula expressed as W x V 1-x O 2 , and

X is less than or equal to 0.02.

9 . The composite of claim 1 , wherein:

a thickness of the second layer is less than or equal to 1 μm.

10 . The composite of claim 1 , wherein:

the second layer is a dielectric spacer layer comprised of at least one of MgF 2 , BaF 2 , and Al 2 O 3 .

11 . The composite of claim 1 , wherein:

the first layer is formed of a material having an optical reflectivity that is greater than 90% for light having a wavelength of greater than or equal to 8 μm and less than or equal to 13 μm.

12 . The composite of claim 1 , wherein:

the third layer is patterned into a plurality of resonators.

13 . The composite of claim 12 , wherein:

the plurality of resonators include a first resonator and a second resonator, and

a width of the first resonator along a first direction is greater than a width of the second resonator along the first direction.

14 . The composite of claim 1 , wherein:

an emissive contrast of the composite between a low-temperature state that reflects light in the infrared (IR) range and a high-temperature state that emits light in the IR range is greater than 50%.

15 . The composite of claim 1 , further comprising:

a structure defining an environment; and

a surface of the structure, wherein the surface is coated with a coating comprising the first, second, and third layers, and a temperature of the environment is maintained wherein,

in response to a temperature of the phase change material being greater than the transition temperature, the coating is configured to radiate light in the infrared spectrum, and

in response to the temperature of the phase change material being less than the transition temperature, the coating is configured not to radiate light in the infrared spectrum.

16 . The composite of claim 1 , wherein:

the second layer includes at least one element in common with the first layer.

17 . A method for manufacturing a composite, the method comprising:

providing a second layer on a first layer, the second layer comprising a material that is lattice-matched to a lattice of the first layer; and

depositing a third layer on the second layer, wherein:

the third layer constitutes a phase change material characterized by a transition temperature, and

the phase change material includes a dopant.

18 . The method for manufacturing the composite of claim 17 , further comprising

patterning the third layer to form a plurality of resonators.

19 . The method for manufacturing the composite of claim 17 , wherein

the transition temperature of the phase change material decreases as the concentration of the dopant in the phase change material increases.

20 . The method for manufacturing the composite of claim 17 , wherein:

the third layer is deposited by magnetron sputtering followed by annealing, and the third layer is patterned by:

forming a spin coat resist on the third layer, baking the spin coat resist,

performing electron beam lithography on the baked spin coat resist, and

after performing the electron beam lithography, performing reactive ion etching of the third layer to form a plurality of resonators.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 8, 2022
From: MIRAGLIOTTA, JOSEPH A.; SHREKENHAMER, DAVID B.; STRIKWERDA, ANDREW C.; HUNT, GABREILLA M.
To: THE JOHNS HOPKINS UNIVERSITY
Reel/Frame 061693/0672 →
Continuity (2)
Provisional Application 63271864 · Oct 26, 2021
Related Publication 20230126472A1 · Apr 27, 2023
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