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 - Frédéric Restagno (LPS, Univ. Paris-Sud)
FRICTION AT MICRO AND MACRO-SCALE
Friction is a common phenomenon that occurs when to objects are force to move tangentially relatively to each other. During this seminar, we shall present two series of experiments concerning friction at macro and micro-scale.
In a first set of experiment [1], we will study the aptitude of surface with anchored polymer chains to transmit stress through the interface. More precisely, we investigate the friction of a PDMS elastomer sliding on a brush of the same polymer in the dynamical regime, as a function of sliding velocity, grafting density and molecular weight of the tethered chains. At high density, the chains are confined outside the elastomer and the rheology of the thin layer can be studied.
Figure 1 : Car hold by two interleaved phonebooks. Copyrights France 5/2p2l.
In a second set of experiment, we will focus on another question related to friction : why can we hold a car with two interleaved phonebooks. We have studied the force needed to separate two books as a function of the number of sheets, the thickness of the sheets, and the interleaving distance in a systematic way [2]. We have shown that the strength of the system is due to the operator : the person, car, truck amplifies any small friction arising from the normal force acting on the boundaries of the stack. We have proposed for the first time a model that captures all the data into a single mastercurve. The study of this complex network provides insight into friction with some connections to MEMS, mooring a ship, interactions between DNA and bacteriophage capsid, and even a toy known as the Chinese finger trap.
[1] C. Cohen, F. Restagno, C. Poulard, and L. Léger, Soft Matter 7, 8535 (2011).
[2] H. Alarcón, T. Salez, C. Poulard, J.-F. Bloch, É. Raphaël, K. Dalnoki-Veress, and F. Restagno, Phys. Rev. Lett. 116, (2016).
Séminaires (4)
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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.
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- Séminaire de Mécanique des Fluides de l’Institut Jean le Rond d’Alembert
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