Three dimensional interconnected porous graphene-based thermal interface materials

1. A composite structure comprising:

a thermal interface material for increasing thermal conduction or thermal dissipation across an interface between a heat source and a heat sink, the thermal interface material comprising:

the heat source;

the heat sink;

an interface with the heat source, the heat source transmitting heat to the thermal interface material;

an interface with the heat sink, the heat sink accepting heat across the thermal interface material for dissipation from the thermal interface material to the heat sink;

a three-dimensional interconnected porous graphene (3D-IPG) foam structure constructed of three-dimensional interconnected porous graphene sheets formed as a plurality of layers between the interface with the heat source and the interface with the heat sink, the graphene sheets having an flexible interconnection architecture, and arranged as an interface layer to reduce thermal resistance between mating surfaces, under compressive pressure, when maintained under said compressive pressure, thereby providing high interfacial thermal conductance and a high interface contact area, said interface layer not fully extending to the edge of the interface; and

an encapsulant material extending around a perimeter of the interface so as to seal or substantially seal the interface layer, so that the encapsulant material covers the edges of the interface,

wherein the flexible interconnection architectures allow the 3D-IPG to maintain a high interfacial thermal conductance or thermal dissipation by the 3D-IPG filling a gap between the heat source and the heat sink across the interface layer, and by capping small features up to nanoscale roughened surfaces.

2. The composite structure of claim 1 , wherein the creating a pressure insensitive thermal interfacial resistance, in turn results in the 3D-IPG functioning as an effective heat dissipater, heat sink or heat convector.

3. The composite structure of claim 1 , further comprising:

the interconnected graphene sheets produced by constructing the 3D-IPG films with graphene sheets having a thickness range of approximately 1 nm to approximately 10 nm.

4. The composite structure of claim 1 , further comprising:

the graphene sheets produced from high-temperature chemical vapor deposition (CVD) based templating formed from a sacrificial template.

5. The composite structure of claim 1 , further comprising:

the graphene sheets produced from high-temperature chemical vapor deposition onto porous Ni foam to produce graphene-supported Ni foam, with the Ni foam acting as a sacrificial template for graphene deposition, and the graphene-supported Ni foam treated with etchant to remove the Ni and leave free-standing porous graphene film, followed by transferring the graphene film onto a substrate acting as heat source or heat sink.

6. The composite structure of claim 1 , further comprising:

the graphene sheets produced from solution-grown 3D porous graphene oxide or reduced graphene oxides.

7. The composite structure of claim 1 , further comprising the 3D-IPG modified or filled by at least one of the group consisting of an additive or filler, said additive or filler enhancing at least one of thermal conductivity and mechanical strength.

8. The composite structure of claim 7 , wherein the additive or filler comprises a material applied by chemical/electrochemical deposition of metal/metal oxide nanoparticles on the inner walls/pores of the 3D-IPG; by infiltration or by physical deposition of conductive metals, metal oxides, ceramics, particles or fibers, conductive polymer or phase change materials on the inner walls/pores of 3D-IPG.

9. A method of producing the composite structure of claim 1 , the method comprising:

providing a three-dimensional interconnected porous graphene (3D-IPG) foam structure constructed of three-dimensional interconnected graphene sheets formed as a plurality of monolayers by chemical vapor deposition (CVD) from a sacrificial template, the graphene sheets having an interconnection architecture;

placing the 3D-IPG porous foam structure at an interface between a heat source and a heat sink and applying pressure across the interface, said 3D-IPG porous foam not fully extending to the edge of the interface; and

providing the encapsulant material extending around the perimeter of the interface so as to seal or substantially seal the interface layer,

wherein the 3D-IPG foam structure provides a flexible interconnection architectures, allowing the 3D-IPG to maintain a high interfacial thermal conductance by the 3D-IPG filling a gap between a heat source and a heat sink across the interface, thereby reducing thermal resistance between the mating surfaces and providing high thermal conductivity and a high interface contact area to 3D-IPG function as an effective heat dissipater, heat sink or heat convector.

10. The method of claim 9 , further comprising:

using the deposition conditions to allow the 3D-IPG to maintain a high thermal conductivity; and

using the 3D-IPG as an interface by filling the gap between the heat source and the heat sink across the interface, and by capping small features up to nanoscale roughened surfaces, thereby reducing thermal resistance between the mating surfaces, thereby providing high interfacial thermal conductance and a high interface contact area, and creating a pressure insensitive thermal interfacial resistance.

11. The method of claim 9 , further comprising:

constructing the 3D-IPG films with graphene sheets having a thickness range of approximately 1 nm to approximately 10 nm.

12. The method of claim 9 , further comprising:

producing the interconnected graphene sheets from high-temperature chemical vapor deposition based templating.

13. The method of claim 9 , further comprising:

producing the interconnected graphene sheets from high-temperature chemical vapor deposition onto porous Ni foam to produce graphene-supported Ni foam, with the Ni foam acting as a sacrificial template for graphene deposition, and the graphene-supported Ni foam treated with etchant to remove the Ni and leave free-standing graphene porous film, followed by transferring the graphene film onto a substrate acting as heat source or heat sink.

14. The method of claim 9 , further comprising:

producing the interconnected graphene sheets from solution-grown 3D porous graphene oxide or reduced graphene oxides.