Topology-Changing Broadband Metamaterials Enabled by Closable Nanotrenches

Area of Science:

• Photonics and Materials Science
• Nanotechnology and Metamaterials

Background:

• Mechanical strain is a common method for controlling optical functionalities in metamaterials.
• However, traditional strain methods often preserve material symmetries and topologies, limiting multifunctional capabilities.

Purpose of the Study:

• To present a novel approach for topology manipulation in metamaterials using mechanically actuated nanotrenches.
• To demonstrate the ability to abruptly switch metamaterial functionalities by altering their topology.

Main Methods:

• Fabrication of metamaterials on flexible substrates with embedded, closable nanotrenches of diverse geometries.
• Application of mechanical bending to the substrate, inducing nanotrench closure and topological changes.

Main Results:

• Achieved abrupt switching of metamaterial functionalities including resonance, chirality, and polarization selectivity.
• Demonstrated robust performance with 99.9% extinction, stable over a thousand bending cycles.
• Showcased applicability across a broadband spectrum (visible to microwave).

Conclusions:

• Mechanically closing/opening nanotrenches offers a powerful method for topology manipulation and active control of metamaterial functionalities.
• This wafer-scale platform enables dynamic control for quantum plasmonics and subnanometer photonic applications.