Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 19 of 19 for “"phononic crystals"”.
-
Hypersonic phononic crystals
… properties. This thesis explores hypersonic phononic crystals as means to achieve control over high frequency acoustic phonons. An integrated approach to fabrication, measurement and analysis of hypersonic phononic crystals with band gaps in the GHz range is presented. First, the phonon …
-
Mechanical bound states in the continuum in phononic crystals
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2026-08-01
-
Investigating the Existence of Coherent Phonon Scattering in Silicon Using Phononic Crystals
… of phonons scattered from the inclusions in the phononic crystal. The intent of this work is to investigate the existence of coherent scattering in Si via phononic crystals. A phononic crystal is a periodic array of inclusions inside a host material. The inclusions could be a second material or a …
-
Design optimization of acoustic metamaterials and phononic crystals with a time domain method
… optimizations of acoustic metamaterials and phononic crystals is presented. The gradient-based design procedure is suitable for large numbers of design variables, and results are shown on achieving effective material properties with a unit cell and the broadband noise reduction with periodic …
-
2D and 3D periodic templates through holographic interference lithography : photonic and phononic crystals and biomimetic microlens arrays
… including such diverse areas as photonic crystals, phononic crystals, drug delivery, microtrusses, tissue scaffolds, microfluidics and colloidal crystallization. A correlation between structure and photonic band gap properties was established by systematically exploring the 11 FCC space …
-
THEORY, FABRICATION, AND EXPERIMENTATION OF PHONONIC CRYSTALS IN MEMS AT MICRO/NANO SCALE: ENGINEERING OF THERMAL AND RF PHONONS TO APPLICATIONS IN THERMOELECTRICS AND MICRORESONATORS
<p>Phononic Crystals (PnCs) are novel materials comprised of a periodic structure of inclusions in a matrix. This periodic arrangement creates phononic bandgaps, and modifies phononic bandstructures of a material. Such a property offers promising applications at the micro and nano scales to …
-
Modeling and characterization of elastic wave propagation in micro-scale photonic crystals
Micro-scale phononic crystals are micro-electro-mechanical-systems (MEMS) made of one material periodically embedded in another material, leading to periodic changes in elastic properties of the composite structure. Such devices exhibit elastic bandgaps, which are very useful in many commercial …
-
Generalized phononic networks : of length scales, symmetry breaking and (non) locality : "controlling complexity through simplicity"
… from sound insulation to heat management. Phononic crystals and metamaterials are artificially structured materials (at certain length scales) that provide promise in controlling the propagation of phonons in solids. However, the vector nature of the phonon makes the development of a …
-
Photoexcited hypersonic surface acoustic waves propagating under periodic metal grating
… on the duty cycle in design of hypersonic phononic crystals. Further, we conduct finite element based eigenmode analysis on the Si-Al periodic composite which show a good agreement with the experimental data. Modal analysis further reveals that higher attenuation in the duty cycle regime …
-
Polyoxometalates and Block Copolymers: Templated Self-Assembly for Nanomaterials Applications
… often present unique features. From photonic and phononic crystals to semi-conductors, the periodic structuring of materials has found widespread use in areas such as computing, catalysis, and energy conversion. Magnonic crystals are periodically ordered magnetic materials that are able to …
-
Controlling radial waves through effective periodicity
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-12-01
-
Thermally tunable band gaps in architected metamaterial structures
The combined characteristics of periodicity and locally resonant features in metamaterial structures, or meta-structures, give rise to unique wave propagation characteristics such as relatively low and wide band gaps. These meta-structures have a fixed geometry and thus a fixed behavior, however …
-
Dynamic Homogenization Of Linear Waves In Periodic Media And Origami-Inspired Structures
This dissertation aims to establish a comprehensive analytical framework for dynamic homogenization of wave motion at arbitrary frequency in (i) “perforated” periodic con- tinua, and (ii) periodic origami-inspired structures described via “bar-and-hinge” com- putational paradigm. For a given …
-
Mechanics of magneto-active elastomers and applications to magnetically-tunable metamaterials
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2026-05-01
-
Nonlinear wave dynamics of continuum phononic materials with periodic rough contacts
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2024-03-01 without embargo terms
-
Φωτονικά και φωνονικά υλικά
Στην παρούσα Διδακτορική Διατριβή διερευνώνται αριθμητικά δομές οι οποίες μπορούν να λειτουργήσουν ως φωνονικά ή φωτονικά υλικά. Βασικό χαρακτηριστικό των φωτονικών και των φωνονικών υλικών είναι η ύπαρξη χασμάτων συχνοτήτων στη διάδοση των ηλεκτρομαγνητικών και των ελαστικών κυμάτων αντίστοιχα …