ESPCI web site
Le séminaire hebdomadaire du laboratoire PMMH a lieu tous les vendredis à 11h, au premier étage Barre Cassan, campus Jussieu (plan).
Stéphane Perrard
Etienne Reyssat
Virgile Thiévenaz
PMMH
BARRE CASSAN
BAT A 1ER ETAGE CASE 18
7 QUAI SAINT BERNARD
75005 PARIS
France
Tel : (33) 1 40 79 45 22
Séminaire PMMH - Jean Comtet (EPFL)
Soft matter and mechanics at the molecular scale : from the rheology of few-atoms gold junctions to the observation of single proton transport at solid/water interfaces.
Jean Comtet
École Polytechnique Fédérale de Lausanne,
Département Sciences et Techniques de l'Ingénieur,
CH-1015 Lausanne
New paradigms are expected to emerge at the nanometer scale for soft matter and mechanics, stemming from the breakdown of continuum concepts and the appearance of new force scales. I will present in this talk two questions related to the dynamics of soft condensed matter at the molecular scale, addressed using state-of-the-art experimental techniques.
First, I will show how we can take advantage of Quartz-Tuning Fork based Atomic Force Microscopy to uncover the yielding and rheological properties of gold junctions of only few atoms. In particular, I will show that these molecular systems exhibit a liquid-like fluidized response under large strain. This behavior challenges existing frameworks for plastic flow in defect-free crystalline systems, but exhibits surprising similarities with that of macroscopic soft yielding materials [1].
Second, I will show how we can use optical super-resolution techniques to probe the transport of single proton charges at solid/water interfaces. Our approach relies on the successive protonation and activation of optically active defects at the surface of hexagonal boron nitride crystals, allowing us to resolve interfacial proton transport at the single molecule scale with nanometric resolution and over micrometer range. These observations provide a direct demonstration that interfacial water provides a preferential pathway for lateral proton transport [2].
[1] Atomic rheology of gold nanojunctions. Nature, 1476-4687 (2019).
J. Comtet, A. Lainé, A. Niguès, L. Bocquet, A. Siria.
[2] Direct observation of water mediated single proton transport between hBN surface defects. arXiv preprint arXiv:1906.09019 (2019).
J. Comtet, B. Grosjean, E. Glushkov, A. Avsar, K. Watanabe, T. Taniguchi, R. Vuilleumier, Marie-Laure Bocquet, A. Radenovic
Séminaires (4)
-
Séminaire PMMH - Francesca Borghi Università degli Studi di Milano
Vendredi 20 juin de 11h00 à 12h00 - Salle réunion PMMH 1
REPROGRAMMABLE HARDWARE FOR DATA PROCESSING AT THE EDGE : A NEW COMPUTING PARADIGM BASED ON NEUROMORPHIC SYSTEMS
The brain's ability to perform efficient and fault-tolerant data processing is strongly related with its peculiar interconnected adaptive architecture, based on redundant neural circuits interacting at different scales. By emulating the brain's processing and learning mechanisms, computing technologies strive to (…) -
Séminaire PMMH - Francesca Borghi Università degli Studi di Milano
Vendredi 20 juin de 11h00 à 12h00 - Salle réunion PMMH 1
REPROGRAMMABLE HARDWARE FOR DATA PROCESSING AT THE EDGE : A NEW COMPUTING PARADIGM BASED ON NEUROMORPHIC SYSTEMS
The brain's ability to perform efficient and fault-tolerant data processing is strongly related with its peculiar interconnected adaptive architecture, based on redundant neural circuits interacting at different scales. By emulating the brain's processing and learning mechanisms, computing technologies strive to (…) -
Séminaire PMMH - Salvatore Federico (University of Calgary, Canada)
Vendredi 4 juillet de 11h00 à 12h00 - Salle réunion PMMH 1
Continuum Mechanics of Hydrated Fibre-Reinforced Soft Tissues
Biological tissues can be represented as bi-phasic continua, with a porous solid phase saturated by an interstitial fluid and reinforced by collagen fibers. This lecture will give an overview of the modelling techniques for fibre-reinforced porous composite materials with statistical orientation of the fibers. Both (…) -
Séminaire PMMH - Salvatore Federico (University of Calgary, Canada)
Vendredi 4 juillet de 11h00 à 12h00 - Salle réunion PMMH 1
Continuum Mechanics of Hydrated Fibre-Reinforced Soft Tissues
Biological tissues can be represented as bi-phasic continua, with a porous solid phase saturated by an interstitial fluid and reinforced by collagen fibers. This lecture will give an overview of the modelling techniques for fibre-reinforced porous composite materials with statistical orientation of the fibers. Both (…)
Instructions générales pour les conférenciers
Le public du séminaire est très hétérogène (rien qu’au PMMH nous travaillons sur des thématiques très diverses, mécanique des fluides, des milieux granulaires, des solides, physique statistique, physique du mouillage, micro-fluidique, biophysique,...) l’objectif est donc de ne pas faire un séminaire trop spécialiste : au moins la première moitié du séminaire à un niveau accessible pour celui qui ne connaît rien sur le sujet.
Le séminaire a lieu à 11h. rendez-vous 15 minutes avant pour installer et tester la projection.
Le séminaire dure environ 45 minutes pour laisser un peu de temps pour discuter à la fin.
- Séminaires ESPCI-ENS de biophysique
- Séminaires du Département de Physique de l’ENS
- Séminaires du Laboratoire d’Hydrodynamique de l’X
- Séminaire de Mécanique d’Orsay (page web FAST)
- Séminaire de Mécanique d’Orsay (page web LIMSI)
- Séminaire de Mécanique des Fluides de l’Institut Jean le Rond d’Alembert
- Séminaires du laboratoire MSC, Paris VII
- Séminaires Gulliver
Lien vers séminaires café (internes, tous les jeudis)
