This paper summarizes our recent research efforts to realize efficient electrically small antenna (EESA) systems based on ideal analytical and numerical metamaterial-based antenna systems, and physically realized metamaterial-inspired antenna designs. Our theoretical and numerical studies of the radiation and resonance behaviors of the proposed metamaterial-based EESA systems, as well as our ef...

Enhancement of structure-borne wave energy harvesting is investigated by exploiting metamaterial-based and metamaterial-inspired electroelastic systems. The concepts of wave focusing, localization, and funneling are leveraged to establish novel metamaterial energy harvester (MEH) configurations. The MEH systems transform the incoming structure-borne wave energy into electrical energy by couplin...

Wave propagation can be manipulated at a deep subwavelength scale through the locally resonant metamaterial that possesses unusual effective material properties. Hyperlens due to metamaterial's anomalous anisotropy can lead to superior-resolution imaging. In this paper, a single-phase elastic metamaterial with strongly anisotropic effective mass density has been designed. The proposed metamater...

Using metamaterial absorbers, we have shown that metallic layers in the absorbers do not necessarily constitute undesired resistive heating problem for photovoltaics. Tailoring the geometric skin depth of metals and employing the natural bulk absorbance characteristics of the semiconductors in those absorbers can enable the exchange of undesired resistive losses with the useful optical absorban...

We propose and demonstrate metamaterial immersion lenses by shaping plasmonic metamaterials. The convex and concave shapes for the elliptically and hyperbolically dispersive metamaterials are designed using phase compensation method. Numerical simulations verify that the metamaterial immersion lenses possess exceptionally large effective numerical apertures thus can achieve deep subwavelength r...

We investigate thermal emission from a metamaterial wire medium embedded in a dielectric host and highlight two different regimes for efficient emission, respectively characterized by broadband emission near the effective plasma frequency of the metamaterial, and by narrow-band resonant emission at the band-edge in the Bragg scattering regime. We discuss how to control the spectral position and...

We numerically and experimentally investigate a planar metamaterial that is composed of connected cut-wire pairs and continuous wires operating at 21 GHz. The characterization was performed by using the effective medium theory. The existence of negative refraction is concluded from the transmission data of four structures: cut-wire pairs, shorted cut-wire pairs, composite metamaterial, and shor...

We demonstrate that spatial arrangement and optical properties of metamaterial nanostructures can be controlled dynamically using currents and magnetic fields. Mechanical deformation of metamaterial arrays is driven by both resistive heating of bimorph nanostructures and the Lorentz force that acts on charges moving in a magnetic field. With electrically controlled transmission changes of up to...

We experimentally demonstrate efficient electro-optical control in an active nano-structured plasmonic metamaterial hybridised with a liquid-crystal cell. The hybridisation was achieved by simultaneously replacing the polarizer, transparent electrode and molecular alignment layer of the liquid-crystal cell with the metamaterial nano-structure. With the control signal of only 7 V we have achieve...

Planar hybrid metamaterial with different split ring resonators (SRR) structure dimensions are fabricated on silicon substrates by femtosecond (fs) laser micro-lens array (MLA) lithography and lift-off process. The fabricated metamaterial structures consist of: (a) uniform metamaterial with 4 SRRs at same design and dimension as a unit cell and (b) hybrid metamaterial with 4 SRRs at same design...