  Featuring dense spatial distributions of engineered metallic particles,
electromagnetic metamaterials exhibit simultaneously negative values of both,
dielectric permittivity and magnetic permeability, within a resonance frequency
band called left-handed passband. Unusual electromagnetic properties are found
resulting in promising applications such as sub-wavelength resolution imaging.
State-of-the-art micro/nanomanufacturing has led to resonance frequencies
reaching the visible red. The common embedding of the metal particles in
plastic matrices or deposition on dielectric substrates within a small area
severely limits the usefulness of the materials. Here, we use UV or X-ray
lithography to build comparably large areas and quantities of the first
freely-suspended matrix-free metamaterials in which the metallic structures are
S-string-like with their ends held by a window-frame. In vacuo spectral
characterization combined with simulation reveals left-handed passbands from
1.6 to 2.2 THz. Owing to their size, the devices can be easily handled. They
offer a straightforward way of making them tunable and two-dimensionally
isotropic.
