Reconfigurable terahertz metamaterial device with pressure memory.

Area of Science:

• Metamaterials
• Microfluidics
• Terahertz Technology

Background:

• Metamaterials offer unique electromagnetic properties.
• Reconfigurable devices are crucial for tunable functionalities.
• Liquid metals present opportunities for dynamic material structuring.

Purpose of the Study:

• To demonstrate a pressure-driven, reconfigurable terahertz metamaterial.
• To investigate the pressure memory effect in liquid metal devices.
• To explore the tunability of terahertz response through mechanical reconfiguration.

Main Methods:

• Fabrication of microfluidic structures in polydimethylsiloxane (PDMS) using soft lithography.
• Injection of eutectic gallium indium (EGaIn) liquid metal into microchannels.
• Utilizing the oxide surface layer of EGaIn for mechanical stabilization.
• Applying controlled pressure to reconfigure the liquid metal geometry.

Main Results:

• Achieved discrete terahertz responses by altering EGaIn geometry.
• Demonstrated switching between split ring, closed ring, and irregular closed ring resonator configurations.
• Observed significant changes in the transmission spectrum with geometric reconfiguration.
• Confirmed pressure memory by the retention of liquid metal morphology after pressure release.

Conclusions:

• The developed liquid metal metamaterial is reconfigurable via applied pressure.
• The device exhibits a notable pressure memory effect.
• This technology enables tunable terahertz responses through mechanical control.