skip to main content

Title: Reconfigurable liquid metal based terahertz metamaterials via selective erasure and refilling to the unit cell level

We demonstrate a technique for selectively erasing and refilling unit cells of terahertz (THz) metamaterials. The structures are formed by injecting eutectic gallium indium (EGaIn), a liquid metal at room temperature, into microchannels within a polydimethylsiloxane (PDMS) mold fabricated using conventional soft lithography techniques. The thin oxide layer that forms on the surface of EGaIn can be locally dissolved via exposure to hydrochloric acid (HCl) introduced at the surface of the gas permeable PDMS mold. In the absence of the oxide skin, the liquid metal retracts to a position where a stable new oxide layer can be formed, effectively erasing the liquid metal structure in the presence of HCl. After erasing selected structures, EGaIn can be re-injected into microchannels to yield the initial structure. In the case of small unit cells, we show that mechanical pressure can be used to effectively erase individual elements. We use THz time-domain spectroscopy to characterize the distinct transmission properties for each of these different structures.
Authors:
; ;  [1] ;  [2]
  1. Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)
  2. Department of Metallurgical Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)
Publication Date:
OSTI Identifier:
22253946
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 103; Journal Issue: 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; EUTECTICS; GALLIUM; HYDROCHLORIC ACID; LAYERS; LIQUID METALS; OXIDES; SPECTROSCOPY; SURFACES