Thermal Metamaterials and Heat Flux Manipulation

Thermal metamaterials are engineered composites designed to direct and control the flow of heat in ways that lie beyond the capabilities of natural materials. By spatially organising constituent elements with distinct thermal conductivities, these artificial structures enable unprecedented manipulation of heat diffusion, radiation and convection. Recent advances have demonstrated a rich portfolio of functionalities, including cloaking hot regions to render objects thermally invisible, concentrating thermal energy to enhance energy harvesting, rotating heat currents to create thermal illusions and dynamically tuning conductive pathways. Underpinned by concepts from transformation thermodynamics, topology optimisation and moiré geometry, researchers now achieve highly customisable, background-independent and shape-adaptive devices. Practical applications span thermal management in electronics, steady and transient radiative camouflage, solar-thermal energy conversion and thermal information processing. The global significance of this field is underscored by its potential to improve energy efficiency, advance stealth technologies and enable multifunctional thermal systems in industrial, environmental and defence sectors.

Research from Nature Portfolio

In 2024 a novel twisted moiré thermal metasurface demonstrated that by rotating bilayer thermal patterns at a critical angle, heat diffusion can switch between cloaking and concentrating modes. This experiment revealed a thermal analogue of twistronics, introducing a “magic angle” for diffusive heat that enables tunable heat routing without reliance on wave-like dispersion. Earlier work conceived an analog thermal material whose conductivity can be continuously tuned from near zero to near infinity by varying a spinning core’s rotation speed, thus providing a single device with flexible and anisotropic heat-flux control. In 2021 researchers introduced a freeform, 3D-printable paradigm in which topology-optimised cells are assembled into complex shapes, yielding omnidirectional concentrating, rotating and cloaking functionalities that are independent of the background and amenable to rapid prototyping.

Thermal Metamaterials and Heat Flux Manipulation publication trend

The graph below shows the total number of articles in thermal metamaterials and heat flux manipulation across all publications each year (not limited to Nature Index journals).

Technical terms

Thermal metamaterial: An artificial composite engineered with spatially varying thermal properties to control the conduction, radiation or convection of heat beyond natural limitations.

Heat flux: The rate of heat transfer per unit area, governed by thermal gradients and material conductivities.

Thermal cloaking: The redirection of heat flux around an object to minimise thermal disturbance and render it virtually undetectable to infrared sensing.

Thermal concentrator: A device that guides and focuses heat flux into a designated region, enhancing local temperature or energy harvesting efficiency.

Anisotropic thermal conductivity: Direction-dependent heat conduction achieved by structuring materials so that thermal transport varies with orientation.

References

1. Twisted moiré conductive thermal metasurface. Nature Communications (2024).
2. Tunable analog thermal material. Nature Communications (2020).
3. Robustly printable freeform thermal metamaterials. Nature Communications (2021).
4. Thermal Metamaterials with Configurable Mechanical Properties. Advanced Science (2024).
5. Transformation thermodynamics: cloaking and concentrating heat flux.. Optics Express (2012).
6. Dynamic thermal camouflage via a liquid-crystal-based radiative metasurface. Nanophotonics (2020).