Novel metamaterial structures for non-conventional propagation of acoustic waves

Norbert Cselyuszka

    Research output: Types of ThesisDoctoral Thesis

    Abstract

    Metamaterials are artificial media composed of subwavelength unit cells,
    specifically engineered to exhibit unusual properties in relation to wave
    propagation, generally not found in nature. Most research in this area has
    been dedicated to electromagnetic metamaterials, In this thesis we present
    results in a new multidisciplinary field of metamaterials in acoustics and
    realization of non-conventional wave propagation applying novel
    metamaterial unit cells. The scientific contribution of this dissertation
    comprises three new types of wave propagation modes and their control with
    newly designed metamaterial unit cells. In the thesis, a novel class of
    compressibility-near-zero (CNZ) acoustic propagation, achieved by using
    Helmholtz resonators, is theoretically analyzed and experimentally
    demonstrated. A closed analytical formula for the effective compressibility of
    the proposed unit cell is presented, and the existence of two frequencies
    which may support CNZ propagation is shown. Furthermore, a new unit cell
    with effective mass density with Lorentzian type behavior is proposed, a
    closed analytical formula for its effective mass density is found, and the
    evanescent, left-handed propagation and density-near-zero acoustic wave
    propagation аre demonstrated. In the end it is demonstrated for the first time
    that a surface acoustic wave propagating at the boundary between a fluid
    and a hard grooved surface can be efficiently controlled by varying only the
    temperature of the fluid, while the geometry of the grooved surface remains
    unchanged. This opens up a way for a number of new applications, all easily
    tunable by external means. Following theoretical considerations, we
    demonstrate temperature-controlled sound trapping and its applications in
    acoustic spectral analysis and temperature sensing. We also present a
    temperature-controlled gradient refractive index (GRIN) acoustic medium and
    apply it to achieve temperature-controlled acoustic focusing.
    Original languageEnglish
    QualificationDoctor of Philosophy
    Awarding Institution
    • University of Novi Sad
    Award date16 Dec 2015
    Publication statusPublished - 2015

    Fingerprint

    Dive into the research topics of 'Novel metamaterial structures for non-conventional propagation of acoustic waves'. Together they form a unique fingerprint.

    Cite this