Metamaterial-Based Electromagnetic Energy Harvesting

Metamaterial-based electromagnetic energy harvesting exploits artificially structured media to capture ambient radio-frequency (RF) and microwave signals and convert them into usable electrical power. By arranging subwavelength resonant elements into periodic lattices or two-dimensional metasurfaces, these devices achieve tailored absorption, field enhancement and wide angular and polarization tolerance. Incoming electromagnetic waves are coupled into resonant circuits—often realised with split-ring resonators, complementary patterns or pixelated unit cells—and directed via power-combining networks to rectifying circuits. Advances in topology optimisation and circuit integration have pushed harvesting efficiencies beyond 60 percent under realistic power densities, enabling self-powered sensors, Internet-of-Things nodes and wireless-powered networks. The combination of multiband operation, insensitivity to incidence angle and miniaturised form factors highlights the potential of metamaterial harvesters to supplement or replace batteries in distributed, low-power applications.

Research from Nature Portfolio

Recent studies have introduced dual-polarised metasurfaces that capture energy from arbitrary incident angles and convert it with high efficiency. One approach employs a supercell array of alternating vias and resonators channelled to a rectification network, achieving radiation-to-AC conversion above 90 percent and AC-to-DC conversion near 80 percent at 2.4 GHz. A follow-up design uses pixelated unit cells optimised by binary topology algorithms to target two frequency bands simultaneously. This metasurface delivers near-unity absorption at 2.45 GHz and 6 GHz, irrespective of polarisation, and has been validated experimentally with full-wave absorption exceeding 95 percent, demonstrating the power of geometry optimisation in multiband energy harvesting.

Metamaterial-Based Electromagnetic Energy Harvesting publication trend

The graph below shows the total number of articles in metamaterial-based electromagnetic energy harvesting across all publications each year (not limited to Nature Index journals).

Technical terms

Metamaterial: An engineered assembly of subwavelength elements designed to exhibit electromagnetic properties not found in natural materials.

Metasurface: A two-dimensional analogue of metamaterials comprising patterned subwavelength resonators that control wavefronts and absorption.

Split-ring resonator: A metallic ring with a narrow gap acting as a magnetic LC resonator for selective frequency absorption.

Rectenna: A device combining an antenna or metasurface with a rectifying circuit to convert RF energy into direct-current power.

Polarization-insensitive: The ability of a device to absorb electromagnetic waves regardless of the orientation of their electric field.

Impedance matching: The design practice of equalising source and load impedances to minimise reflection and maximise power transfer.

References

1. Harvesting the Energy of Multi-Polarized Electromagnetic Waves. Scientific Reports (2017).
2. Pixelated Metasurface for Dual-Band and Multi-Polarization Electromagnetic Energy Harvesting. Scientific Reports (2018).
3. A dual-band, polarization-insensitive, wide-angle metasurface array for electromagnetic energy harvesting and wireless power transfer. Results in Physics (2023).
4. Design and fabrication of a 2D-isotropic flexible ultra-thin metasurface for ambient electromagnetic energy harvesting. AIP Advances (2019).
5. Polarization-Insensitive Fractal Metamaterial Surface for Energy Harvesting in IoT Applications. Electronics (2020).