Τμήμα Επιστήμης & Τεχνολογίας Υλικών
06 Δεκεμβρίου 2023
Τίτλος
«3-D Mechanical Metamaterials»
του Σταύρου Σκρεπετού
μεταπτυχιακού φοιτητή του Τμήματος Επιστήμης και Τεχνολογίας Υλικών του Πανεπιστημίου Κρήτης
Επιβλέπουσα: Μαρία Φαρσάρη
Δευτέρα 11 Δεκεμβρίου 2023
Ώρα 10:00
H παρουσίαση θα πραγματοποιηθεί στην Αίθουσα 1 του Ιδρύματος Τεχνολογίας και Έρευνας, στο κεντρικό κτήριο του ΙΤΕ
Abstract
"This study highlights the integration of metamaterials into tissue engineering, leveraging expertise from physical sciences, computational modeling, and mechanical biology. Mechanical metamaterials offer unique advantages for controlling the mechanical environment of cells and tissues, including the creation of specialized cellular structures and properties.The primary objective was to design precise spherical mechanical metamaterials with rare auxetic behavior, achieved through algorithmic engineering facilitated by the Hyperganic software. The spheres were fabricated with high precision using advanced 3D printing and optically characterized through scanning electron microscopy (SEM).
Multi – Photon lithography enabled the construction of intricate microscale structures, particularly the fabrication of 400 μm-diameter spherical scaffolds. These scaffolds are promising for supporting cell growth without compromising viability, making them valuable for tissue engineering. Characterization involved numerical simulations using ANSYS and SolidWorks and mechanical testing with the MicroTester LT to calculate key properties. Mesenchymal stem cells were seeded on the scaffolds and assessed over multiple days. Precise 3D analysis was made possible through a confocal microscope, allowing a deep understanding of these innovative metamaterial-based tissue engineering solutions."
05 Δεκεμβρίου 2023
Δείτε τη σχετική ανακοίνωση.30 Νοεμβρίου 2023
Το Πανεπιστήμιο Κρήτης θα χορηγήσει κατά το ακαδημαϊκό έτος 2022-23, δύο (2) Βραβεία Αριστείας με την επωνυμία «Έπαθλον Καθηγήτριας Ζωής Δημητριάδη».
Οι αιτήσεις θα παραλαμβάνονται ηλεκτρονικά (postgrad.secr@uoc.gr) από την κ. Σοφία Γιαλεδάκη. Καταληκτική ημερομηνία κατάθεσης των δικαιολογητικών 21η Δεκεμβρίου 2023.
Eπισυνάπτonται:24 Νοεμβρίου 2023
Δείτε τη συνημμένη πρόσκληση.21 Νοεμβρίου 2023
Δείτε για πληροφορίες εδώ.21 Νοεμβρίου 2023
Αγαπητές φοιτήτριες και αγαπητοί φοιτητές,Η Επιτροπή Αξιολόγησης σας καλεί να συμμετάσχετε ενεργά στην ηλεκτρονική εσωτερική αξιολόγηση των εκπαιδευτικών διαδικασιών του Προπτυχιακού και Μεταπτυχιακού Προγράμματος Σπουδών, για το Χειμερινό Εξάμηνο του Ακαδημαϊκού Έτους 2023-2024, η οποία ξεκινά στις 20 Νοεμβρίου 2023 και ολοκληρώνεται την 1 Δεκεμβρίου 2023. Η υψηλή συμμετοχή των φοιτητών στην αξιολόγηση αυξάνει τη βαρύτητα των αποτελεσμάτων και συντελεί στην αναβάθμιση των παρεχόμενων εκπαιδευτικών και διοικητικών υπηρεσιών του Τμήματος. Τόσο τα τυποποιημένα ερωτήματα όσο και το ελεύθερο κείμενο, όπου καλείται κάθε φοιτητής να πει ελεύθερα την άποψη του για το κάθε μάθημα και διδάσκοντα, λαμβάνονται σοβαρά υπόψη από τους διδάσκοντες και το τμήμα για την βελτίωση των προσφερόμενων εκπαιδευτικών υπηρεσιών.
Η αξιολόγηση των μαθημάτων θα γίνει μέσω κουπονιών, τα οποία θα δημιουργηθούν από το πληροφοριακό σύστημα της ΜΟΔΙΠ και θα φέρουν το QR code, το URL του ερωτηματολογίου και τον μοναδικό κωδικό (token) για την συμπλήρωση του κάθε ερωτηματολογίου. Ο διαμοιρασμός των κουπονιών, θα γίνει από την γραμματεία, στους/στις φοιτητές/τριες που είναι παρόντες/ούσες στην αίθουσα. Η αξιολόγηση θα γίνει επιτόπου, ως εκ τούτου θα πρέπει να έχετε μαζί σας κινητό τηλέφωνο smartphone, tablet ή laptop.
Σας ευχαριστούμε για τη συνεργασία.15 Νοεμβρίου 2023
The Engineering School of the University of León is organizing the Blended Intensive Programme Observing and learning from the past to protect our future: water, in collaboration with the University of Bordeaux (France) and the University of Weingarten (Germany). The course offers the possibility of advanced training to Bachelor and Master students and takes place online from the 8th of January to the 11th of February 2024 ( open course followed by moodle) and on-site from the 12th to the 17th of February 2024, at the School of Engineering.
The idea is to prepare a practical course of 40 hours, with recognizement of 3 ECTS credits, about possibilities in the sustainable management of water. There will be a program with online classes, and one week of a physical program full of activities thanks to the short mobility opportunities, to allow the collaboration among the students in international teams.
We will go on very attractive excursions to strategic points where we will be shown the correct use of water, and we will reach milestones in ancient times that are very important internationally. For example, we will visit the largest Roman gold mining in the empire, exploited through the use of water, as well as water purification plants, medieval smithies where it was used as a working tool or energy production plants but in a sustainable and intelligent way, as living examples of options that we have to contribute to a more sustainable and environmentally friendly management of this resource. A space for exchange, which will offer tools to improve the presentation of technical work, learning teaching methodologies such as project-based learning, and all this in an international atmosphere.
We kindly ask you to forward this email to your students, should they be interested in participating in this BIP, and help them in the financing if they will be interested with the new short mobility grants. The deadline for submission of the applications ends on the 1st of December 2023.
For more information, please contact Prof. M. Chatzinikolaidou.03 Νοεμβρίου 2023
ΠΑΝΕΠΙΣΤΗΜΙΟ ΚΡΗΤΗΣ
ΤΜΗΜΑ ΕΠΙΣΤΗΜΗΣ ΚΑΙ ΤΕΧΝΟΛΟΓΙΑΣ ΥΛΙΚΩΝ
ΠΑΡΟΥΣΙΑΣΗ ΜΕΤΑΠΤΥΧΙΑΚΗΣ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ
Τίτλος
«Electrochemically Active Supramolecular Entities in Layered Hybrid Halide Perovskites»
της Ελένης Κωνσταντίνας Μακροπούλου
μεταπτυχιακής φοιτήτριας του Τμήματος Επιστήμης και Τεχνολογίας Υλικών του Πανεπιστημίου Κρήτης
Επιβλέπων Καθηγητής: Κωνσταντίνος Στούμπος
Τετάρτη 8 Νοεμβρίου 2023 Ώρα 10:00
H παρουσίαση θα πραγματοποιηθεί στην αίθουσα Τηλε-εκπαίδευσης (Ε130), στο κτήριο του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών, του Πανεπιστημίου Κρήτης
Abstract
Halide perovskites are exceptional and unconventional semiconductors, known for their high optical absorption coefficients, extended charge carrier diffusion lengths, intense photoluminescence, and slow rates of non-radiative charge recombination [1]. Layered hybrid halide perovskites (AI2BIIX4 or AIIMIIX4, where A represents monovalent or bivalent cations, M represents bivalent p-block metals, and X represents halide anions), feature anionic sheets comprising corner-sharing metal-halide octahedra, selectively partitioned by organic cations, creating crystallographically ordered nanoscale sheets. This unique structure yields natural multiple quantum wells with stable excitonic features, exhibiting intense photoluminescence characteristics, even at room temperature. Intriguingly, a subset of these halide perovskites exhibits broadband optical emission, generating white light via the self-trapped exciton mechanism [2]. Understanding this fascinating trap-activated behavior necessitates careful material design, including the use of various organic spacers that can potentially induce or suppress this effect.
In this study, we have designed and synthesized a series of layered perovskites with electrochemically-active spacers, where the electrochemical state of the spacer influences the materials optical properties. The introduction of functional groups in the spacer cation adds to the structural complexity by engaging in weak supramolecular interactions, acting as perturbation probes to investigate the optical response concerning the electrochemical state of the spacer cation. Specifically, we have synthesized two sister A2PbBr4 compounds (A+ = 2,3 dihydroxy-phenylethylammonium ((HO)2-PEA) and 2-(3-aminoethyl)benzoic acid (HO2C-PEA)) as the redox-active and redox-inert pair of compounds, exhibiting a similar supramolecular interaction environment within the perovskite host. As evidenced by single-crystal X-ray diffraction experiments, the redox-active compound readily crystallizes in its partially oxidized semiquinone form during ambient environment synthesis, exhibiting similar photoluminescence characteristics to the redox-inert compound. These observations suggest formation and rapid quenching of the chemically reactive radical during the reaction. In order to probe this behavior, the reaction system was treated with a variety of chemical redox reagents targeting to obtain the compound in its fully reduced (catechol) and fully oxidized (quinone) form. Simultaneous investigations into the electrocatalytic reaction mechanism using cyclic voltammetry have indicated the presence of both the fully reduced form ((HO)2-PEA)2PbBr4 and the fully oxidized ((O=C)2-PEA)2PbBr4 in solution, prompting further optical and structural characterization of these metastable halide perovskite species.
31 Οκτωβρίου 2023
Επιβλέπων: Παύλος Σαββίδης
(Σύμφωνα με το άρθρο 95, παρ. 3 του Ν. 4957/2022, ΦΕΚ 141 τ. Α΄/21.7.2022)
Την Δευτέρα 6 Νοεμβρίου 2023 και ώρα 12:00 στην αίθουσα Τηλεεκπαίδευσης Ε130 του Τμήματος Μαθηματικών και Εφαρμοσμένων Μαθηματικών του Πανεπιστημίου Κρήτης, θα γίνει η δημόσια παρουσίαση και υποστήριξη της Διδακτορικής Διατριβής του υποψήφιου διδάκτορος του Τμήματος Επιστήμης και Τεχνολογίας Υλικών κ. Εμμανουήλ Μαυροτσουπάκη, με θέμα:
«Development of Perovskite Microcavities Exhibiting Strong Light Matter Coupling and Rashba-Dresselhaus Effects at Room Temperature.»
Abstract
Over the years there has been a grown interest for artificial gauge fields. A synthetic gauge field is the tailoring of specific conditions such that some quantity of neutral particles emulates the dynamics of charged particles in a magnetic field. In condensed matter physics, the spin orbit interaction, can be exploited to influence the movement of electrons through an effective magnetic field. In crystals and heterostructures lacking inversion symmetry, electrons feel the effect of effective spin orbit couplings called Dresselhaus and Rashba, usually combined together to describe their dynamics. Gauge fields due to spin-orbit coupling (SOC) play a central role in a number of exciting phenomena, accurately described topologically, where concepts such as the Berry phase and curvature enter the system Hamiltonian, taking the role of an effective magnetic field.
In this thesis, we realize an artificial gauge field for light in planar DBR microcavities containing perovskite crystals. Perovskites crystals are well known for their huge excitonic binding energy and their robust emission. They are also high anisotropic materials possessing a large linear birefringence. By harnessing these properties, and using a novel fabrication technique, we achieve the observation of strong light matter coupling between optical cavity modes and perovskite excitons at room temperature. Furthermore, the combination of TE-TM polarization splitting and the material’s anisotropy leads to the interaction between the photonic and polaritonic modes, realizing characteristic Rashba-Dresselhaus texture effects with the emergence of an effective magnetic field and nonzero Berry curvature.
These phenomena are described by a derived effective Hamiltonian for a general birefringent material inside a microcavity and can be utilized for the design of artificial gauge fields for light in polaritonic systems with the further advantage of coherent lasing emission at room temperature.