Frequency-Switchable Metamaterial Absorber Injecting Eutectic Gallium-Indium (EGaIn) Liquid Metal Alloy

• Main Authors: Kenyu Ling, Hyung Ki Kim, Minyeong Yoo, Sungjoon Lim
• Format: Article
• Language: English
• Published: MDPI AG 2015-11-01
• Series: Sensors
• Subjects: metamaterial; resonance; microfluidics
• Online Access: http://www.mdpi.com/1424-8220/15/11/28154

In this study, we demonstrated a new class of frequency-switchable metamaterial absorber in the X-band. Eutectic gallium-indium (EGaIn), a liquid metal alloy, was injected in a microfluidic channel engraved on polymethyl methacrylate (PMMA) to achieve frequency switching. Numerical simulation and experimental results are presented for two cases: when the microfluidic channels are empty, and when they are filled with liquid metal. To evaluate the performance of the fabricated absorber prototype, it is tested with a rectangular waveguide. The resonant frequency was successfully switched from 10.96 GHz to 10.61 GHz after injecting liquid metal while maintaining absorptivity higher than 98%.