Cross-Wavelength Hierarchical Metamaterials Enabled for Trans-Scale Molecules Detection Simultaneously.

Area of Science:

• Materials Science
• Nanotechnology
• Sensing Technology

Background:

• Metamaterials show promise in sensing but are often limited to narrow operating bands due to meta-atom feature sizes.
• Achieving ultra-broadband adaptability with a single meta-atom type remains a significant challenge in metamaterial design.

Purpose of the Study:

• To introduce a novel cross-wavelength hierarchical metamaterial construction scheme.
• To achieve simultaneous enhancement of terahertz (THz) resonance and surface-enhanced Raman scattering (SERS) using a single meta-atom.
• To enable simultaneous detection of analytes across multiple length scales (sub-nanoscale to microscale).

Main Methods:

• Designed a single meta-atom incorporating multiple subwavelength structures at different hierarchical levels.
• Fabricated hierarchical metamaterials capable of operating at dual frequencies.
• Developed a proof-of-concept smart sensory packaging utilizing the developed metamaterial.

Main Results:

• The hierarchical metamaterial demonstrated dual-frequency operation and multiple functionalities.
• Simultaneous detection of sub-nanoscale chemical molecules and microscale biomolecules was achieved with a single metamaterial.
• The smart sensory packaging enabled real-time monitoring of bacterial growth and metabolites in food without package opening.

Conclusions:

• The developed hierarchical metamaterial design overcomes limitations of single-band operation.
• This approach enables unprecedented multiscale sensing capabilities with a single device.
• The work provides a valuable example for creating multiscale functional meta-devices for diverse applications.