Τμήμα Επιστήμης & Μηχανικής Υλικών
Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής της κ. Άννας Θεοδώση
20 Ιουνίου 2025
Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής της
κ. Άννας Θεοδώση
Επιβλέπουσα Καθηγήτρια: Μαρία Καφεσάκη
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Τρίτη 24 Ιουνίου 2025 και ώρα 11:00 στην αίθουσα Τηλεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής της υποψήφιας διδάκτορος του Τμήματος Επιστήμης και Μηχανικής Υλικών κ. Άννας Θεοδώση, με θέμα:
«Optical Metamaterials for Advanced Wave Propagation Control»
Περίληψη
This thesis presents a study of advanced artificial electromagnetic structures, namely, metasurfaces and photonic crystals, for nonlinear, sensing, and energy-related applications. It focuses on the the oretical analysis and numerical modeling of the structures under study, using rigorous simulations in the frequency and time domains. Experimental data by collaborators are used for the verification of the designs and the demonstration of the intended functionality and performance. The research is organized into three main thematic areas. The first part of the thesis is dedicated to nonlinear metasurfaces based on graphene. The unique nonlinear and plasmonic roperties of graphene are exploited to propose structures capable of enhancing third-order nonlinear effects. Various metasurface configurations are analyzed, including patterned graphene meta-atoms and hybrid gold–graphene architectures. Using full-wave electromagnetic simulations, the meta-atom geometry is tuned in order to tailor the underlying resonant structure and enhance the nonlinear response. The second part focuses on microwave metasurfaces designed for refractive index sensing and energy harvesting. These include complementary split ring resonators tailored to perform as water and oil quality sensors, as well as metasurfaces with toroidal topologies aimed at efficient energy harvesting. In addition, structures for mechanical strain detection are proposed through designs with resonant properties that respond strongly to applied stress. Finally, the thesis explores photonic crystal structures enhanced with functional material coatings. Emphasis is placed on tailoring the electromagnetic response of dielectric structures through either an optically denser, epsilon near zero, or nonlinear
material coating. Theoretical analysis and simulations demonstrate how such coatings can enable novel functionalities, particularly in the terahertz spectral range. Overall, this work demonstrates the potential of periodic artificial structures which comprise contemporary materials for controlling electromagnetic waves in a broad range of applications and frequencies, from microwaves, to THz, and the near infrared. It lays the groundwork for their future applications in real-world scenarios.
Εξέταση ΜΤΧ μαθήματος “ΜΕΤΥ-446 Ηλεκτρονική Μικροσκοπία Διέλευσης”
26 Μαΐου 2025
Την Παρασκευή 13 Ιουνίου 2025 και ώρα 10.00-12.00 στην αίθουσα Β2 - Χημικού θα πραγματοποιηθεί η εξέταση του MTX μαθήματος “ΜΕΤΥ-446 Ηλεκτρονική Μικροσκοπία Διέλευσης”.Διαδικτυακή ενημέρωση για τις Επαγγελματικές Προοπτικές των Φοιτητών του Τμήματος Επιστήμης και Μηχανικής Υλικών
06 Μαΐου 2025
Το Τμήμα Επιστήμης και Μηχανικής Υλικών και η Δομή Διασύνδεσης και Σταδιοδρομίας του Πανεπιστημίου Κρήτης σας προσκαλούν σε διαδικτυακή εκδήλωση με θέμα τις επαγγελματικές προοπτικές των αποφοίτων του Τμήματος!
Η εκδήλωση απευθύνεται στους φοιτητές του Τμήματος Επιστήμης και Μηχανικής Υλικών αλλά και σε κάθε ενδιαφερόμενο που θέλει να ενημερωθεί για τις επαγγελματικές διεξόδους και τις ευκαιρίες σταδιοδρομίας που προσφέρει το συγκεκριμένο πτυχίο.
Ημερομηνία: Δευτέρα 12/05/2025
Ώρα: 11:00 – 13:00
Πλατφόρμα: Zoom (*)
Πρόσκληση για εισαγωγή στο Μεταπτυχιακό “Materials Science and Engineering” του Τμήματος Επιστήμης και Μηχανικής Υλικών του Πανεπιστημίου Κρήτης / Call for Applications for Studies in the Postgraduate program in Materials Science and Engineering of the University of Crete
24 Απριλίου 2025
See the corresponding announcement for further details.
Deadline for submission of the application and supporting documents for the Postgraduate Program is set for June 20th, 2025. The interviews will take place on June 27th, 2025 between 10:00 - 13:00. There is the possibility of a video conference for candidates living outside Crete.
Διιδρυματικό Πρόγραμμα Μεταπτυχιακών Σπουδών «Βιοϊατρική Μηχανική»
14 Απριλίου 2025
Δείτε την προκήρυξη για την εισαγωγή πτυχιούχων στο ξενόγλωσσο Διιδρυματικό Πρόγραμμα Μεταπτυχιακών Σπουδών «Βιοϊατρική Μηχανική» (MSc Biomedical Engineering) του Πανεπιστημίου Κρήτης για το ακαδημαϊκό έτος 2025-2026.Παρουσίαση Μεταπτυχιακής Διπλωματικής Εργασίας του κ. Εμμανουήλ Ζαφειράκη
08 Απριλίου 2025
ΠΑΝΕΠΙΣΤΗΜΙΟ ΚΡΗΤΗΣ
ΤΜΗΜΑ ΕΠΙΣΤΗΜΗΣ ΚΑΙ ΜΗΧΑΝΙΚΗΣ ΥΛΙΚΩΝ
ΠΑΡΟΥΣΙΑΣΗ ΜΕΤΑΠΤΥΧΙΑΚΗΣ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ
Τίτλος
«RF Rectifier Diodes Based on Carbon Nanotubes»
του Εμμανουήλ Ζαφειράκη
μεταπτυχιακού φοιτητή του Τμήματος Επιστήμης και Μηχανικής Υλικών του Πανεπιστημίου Κρήτης
Επιβλέπων: Γεώργιος Δεληγεώργης
Παρασκευή 11 Απριλίου 2025 Ώρα 11:00
Η παρουσίαση θα πραγματοποιηθεί στην αίθουσα Φ2, στο κτήριο του Τμήματος Φυσικής, του Πανεπιστημίου Κρήτης
Abstract
Rectifiers are important components in many applications such as sensors or power supplies, and their operation at higher frequencies expand their application potential to wireless communications. With the rise of Internet of Things interconnected devices, interest on rectifiers has increased, making scaling down and increasing efficiency of devices crucial for future wireless applications. With research turning to 2D and nanomaterials for this reason, Carbon Nanotubes (CNTs) are one of the most promising, versatile and widely studied materials for the optimization and miniaturization of high frequency devices. Existing CNT rectifiers exhibit cut-off frequencies up to 840 GHz, with potential to reach several THz. Operation frequency of diodes depends on their resistance and capacitance, which are required to be low for high cut-off frequencies. In this work, integrated half-wave rectification diodes based on aligned semiconducting single-wall CNTs are theoretically evaluated, targeting high cut-off frequencies and improved rectification of RF Electromagnetic (EM) signals. Theoretical resistance calculation models are developed, exploring contact and channel resistance, and High-Frequency EM simulations are employed to evaluate two main contact architectures, the common Face-to-Face sheet contacts, and the Interdigitated fingers structure. The latter presents significantly lower resistance, theoretically operating up to the THz band, in contrast to the GHz operation of the Face-to-Face structure. A device consisting of Pd and Ti contacts was fabricated using the Interdigitated fingers contact architecture, on a 1-port co-planar waveguide, and was evaluated in terms of DC and RF performance.
Τελετή Ορκωμοσίας Τμήματος Επιστήμης και Μηχανικής Υλικών της 26/3/2025
17 Μαρτίου 2025
Δείτε την πρόσκληση της Τελετής Ορκωμοσίας Νέων Αποφοίτων του Τμήματος Επιστήμης και Μηχανικής Υλικών της 26/3/2025.
Παρουσίαση μεταπτυχιακής εργασίας του κ. Β. Τσάμπαλλα
16 Δεκεμβρίου 2024
ΠΑΡΟΥΣΙΑΣΗ ΜΕΤΑΠΤΥΧΙΑΚΗΣ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ
Τίτλος
«Synthesis and Functionalization of Monodisperse Lignin Nanoparticles»
του Βασιλείου Τσάμπαλλα
μεταπτυχιακού φοιτητή του Τμήματος Επιστήμης και Μηχανικής Υλικών του Πανεπιστημίου Κρήτης
Επιβλέπουσα Καθηγήτρια: Μαρία Βαμβακάκη
Τρίτη 17 Δεκεμβρίου 2024 Ώρα 16:00
H παρουσίαση θα πραγματοποιηθεί στην αίθουσα Τηλε-εκπαίδευσης (Ε130), στο κτήριο του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών, του Πανεπιστημίου ΚρήτηςAbstract
«Lignin, an abundant biopolymer, is a promising yet underutilized resource in the development of sustainable materials. The study aims to overcome challenges associated with lignin's heterogeneous structure by synthesizing monodisperse lignin nanoparticles through a controlled and reproducible process. The synthesis methodology involves precision engineering to achieve uniform particle size distribution, ensuring enhanced properties and reproducibility. Furthermore, the research explores novel avenues for the functionalization of these lignin nanoparticles, imparting them with tailored properties suitable for diverse applications. The functionalization process involves the incorporation of specific chemical moieties, enabling improved compatibility with various matrices and facilitating the design of advanced materials. The thesis seeks to contribute to the expanding field of green materials by providing a comprehensive understanding of the synthesis and functionalization of monodisperse lignin nanoparticles. The resulting nanoparticles hold promise for applications in biocompatible materials, drug delivery systems, and environmentally friendly composites. This research addresses the challenges in lignin utilization and opens new avenues for sustainable materials with diverse functionalities, paving the way for an eco-friendly and resource-efficient future».Παρουσίαση Μεταπτυχιακής εργασίας του κ. Ιωάννη Σαμψών
16 Δεκεμβρίου 2024
ΠΑΡΟΥΣΙΑΣΗ ΜΕΤΑΠΤΥΧΙΑΚΗΣ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ
του Ιωάννη Σαμψών
μεταπτυχιακού φοιτητή του Τμήματος Επιστήμης και Μηχανικής Υλικών του Πανεπιστημίου Κρήτης
Τίτλος
«Liquid-Liquid Phase Separation: From Polyelectrolytes to Proteins Using Quantitative Phase Microscopy and Dynamic Light Scattering»
Επιβλέπουσα: Εμμανουέλα Φιλιππίδη
Τετάρτη 18 Δεκεμβρίου 2024 Ώρα 14:30
H παρουσίαση θα πραγματοποιηθεί στην αίθουσα Τηλε-εκπαίδευσης (Ε130), στο κτήριο του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών, του Πανεπιστημίου Κρήτης
Abstract
Understanding the thermodynamic stability of materials allows the prediction of material properties and provides information about energy and entropy changes involved in phase transitions. This thesis focuses on the experimental study of liquid-liquid phase separation of intrinsically disordered proteins and oppositely charged polyelectrolytes, in an effort to provide insights and quantitative thermodynamic measurements relevant to biology.
In particular, this work shows the construction of phase diagrams using quantitative phase microscopy for the disordered protein PGL-3 which participates in condensate formation in the C. elegans embryo and readily undergoes liquid-liquid phase separation in vitro. The control parameters explored are temperature and salt. In addition, first steps are undertaken to examine the multimeric state of the protein upon increasing its concentration. However, since proteins are incredibly complex as they comprise structured and unstructured domains, hydrophobic, hydrophilic, polar and charged amino acids, a parallel study of the coacervation between an oppositely-charged pair of a strong and weak polyelectrolytes was launched. Results from both systems will be presented and similarities and differences will be discussed.
Παρουσίαση διδακτορικής διατριβής του κ. Αλέξανδρου Δελτσίδη
13 Δεκεμβρίου 2024
Πρόσκληση σε Δημόσια Παρουσίαση της Διδακτορικής Διατριβής του
κ. Αλέξανδρου Δελτσίδη
Επιβλέπων: κ. Λάππας Αλέξανδρος, Διευθυντής Ερευνών,
Ινστιτούτου Ηλεκτρονικής Δομής και Λέιζερ του Ιδρύματος Τεχνολογίας Έρευνας, Ηράκλειο Κρήτης
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Παρασκευή 20 Δεκεμβρίου 2024 και ώρα 9:30 στην αίθουσα Τηλεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής του υποψήφιου διδάκτορα του Τμήματος Επιστήμης και Μηχανικής Υλικών κ. Αλέξανδρου Δελτσίδη, με θέμα:
«Electron Correlations in Layered Metal Chalcogenides: Structure and Physical Properties»
Abstract
Intercalation of layered iron chalcogenide superconductors with guest species gives access to a gallery of layered phases with enhanced superconducting properties. In these systems, emerging empirical pictures imply a strong relation of the average and local structure with the magnitude of the superconducting transition temperature . Exploring the puzzling saturation of at large interlayer separations, , (average structure), and the role of the geometry of the basic building FeSe4 block (local structure) in tuning the strength of electronic correlations and spin dynamics in these systems, offers an avenue to parameterize conditions that facilitate high . This thesis focuses on variant phases of the Lix(C5H5N)yFe2-zSe2 system with very large .
High-throughput, time-resolved X-ray total scattering, has been employed to establish conditions that enable the synthesis of phase pure product and simultaneously identify the different length-scales that emerge during the growth of the Lix(C5H5N)yFe2-zSe2 expanded lattice phase. In-situ pair distribution function analysis revealed local distortions, involving swollen FeSe4 edge-sharing units, as a consequence of the electron-donating moieties being accommodated in the interlayer space. These non-trivial local distortions were further explored by element-specific (Fe and Se K-edge) X-ray absorption spectroscopy as a function of temperature and the Li content. The work found progressive softening and stretching of the electronically active Fe-layer with elevated Li content—effects that were associated with the presence of Fe-site vacancies. Annealing Lix(C5H5N)yFe2-zSe2 forms a phase with reduced and somewhat lower —an outcome of the modified metal-ligand environment due to reduced doping level. Local structure insights suggest that empirical local structure metrics for growth may become less relevant when the layers are spaced far away. Instead, other parameters such as electron doping level may come into play to leverage high .
Different aspects of the magnetism of these systems are imprinted in two different time scales. These were probed with X-ray emission spectroscopy and inelastic neutron scattering. The Fe Kβ emission spectra shed light on the evolution of instantaneous spin dynamics (10-15 s) and found evidence of strong localized magnetism in the normal state which, due to strong quantum fluctuations, is severely quenched in the superconducting state. However, Hund's coupling appears to play a key role in mediating the development of local moments when cooling towards the correlated state. Inelastic neutron spectra probed the correlated spin dynamics (10- 12 s) and failed to identify strong resonant signals in the superconducting state—akin to similar unconventional systems—enquiring about the role of electronic correlation strength and doping in dampening the intensity of such signals. Insights on the spin-dynamics suggest that intercalation brings about large spin disorder in the normal state, raising questions about the nature of unconventional pairing interactions in systems with very large .
The outcomes highlight that intercalation by insertion of molecular donors in-between the electronically active iron-layers is a viable tool to develop and design the properties of high- Fe-chalcogenides. The sensitive response of their structure on carrier doping points that when interlayer separation is enhanced, reduces electronic screening that aligns with the concept of Hund’s coupling that is central in modifying the pairing strength and further optimizations of superconductivity.