A5055305407- Adhesion, Friction, and Surface Interactions
- Force Microscopy Techniques and Applications
- Hydrogels: synthesis, properties, applications
- Granular flow and fluidized beds
- 3D Printing in Biomedical Research
- Brake Systems and Friction Analysis
- Material Dynamics and Properties
- nanoparticles nucleation surface interactions
- Cellular Mechanics and Interactions
- Textile materials and evaluations
- Mechanical stress and fatigue analysis
- Rheology and Fluid Dynamics Studies
- Polysaccharides Composition and Applications
- Theoretical and Computational Physics
- Solidification and crystal growth phenomena
- Advanced Materials and Mechanics
- Collagen: Extraction and Characterization
- Tendon Structure and Treatment
- Pickering emulsions and particle stabilization
- Elasticity and Material Modeling
- Block Copolymer Self-Assembly
- Proteins in Food Systems
- biodegradable polymer synthesis and properties
- Surgical Sutures and Adhesives
- Fluid Dynamics and Heat Transfer
Sorbonne Université
2012-2025
Institut des NanoSciences de Paris
2010-2025
Centre National de la Recherche Scientifique
2012-2025
Université Paris Cité
2002-2024
Laboratoire Mécanique des Solides
2022
UPMC Health System
2017
Délégation Ile-de-France Villejuif
2017
Cornell University
2008
Génomique Fonctionnelle des Tumeurs Solides
2000-2003
Délégation Paris 7
2003
We perform an extensive study of the dry-friction dynamics a paper-on-paper system. explore dynamical phase diagram by systematically varying relevant control parameters (driving velocity V, slider mass M, and loading machine stiffness k). A set experimental results gives strong proof that low-velocity is controlled creep process, in agreement with previous from rock mechanics metals [C. H. Scholz, The Mechanics Earthquakes Faulting (Cambridge University Press, Cambridge, 1990), Chap. 2...
We review the present state of understanding solid friction at low velocities and for systems with negligibly small wear effects. first analyze in detail behavior interfaces between macroscopic hard rough solids, whose main dynamical features are well described by Rice–Ruina rate state-dependent constitutive law. show that it results from two combined effects: (i) threshold rheology nanometer-thick junctions jammed under confinement into a soft glassy structure (ii) geometric aging, i.e....
Tendon formation and repair rely on specific combinations of transcription factors, growth mechanical parameters that regulate the production spatial organization type I collagen. Here, we investigated function zinc finger factor EGR1 in tendon formation, healing, using rodent animal models mesenchymal stem cells (MSCs). Adult tendons Egr1-/- mice displayed a deficiency expression genes, including Scx, Col1a1, Col1a2, were mechanically weaker compared with their WT littermates. was recruited...
We report the first part of an extensive study friction at a multicontact interface between nominally flat bodies, rough on micrometer scale, made polymer glasses. Temperature is controlled 20 $\ifmmode^\circ\else\textdegree\fi{}$C and glass transitions poly(methyl metacrylate) polystyrene. In this article, we focus static force. The threshold to macroscopic slip increases with contact time. Increasing temperature found accelerate markedly aging process. This effect correlated strong...
We report an extensive study of dynamic friction at nonlubricated multicontact interfaces between nominally flat bodies, rough on the micrometer scale, made identical polymer glasses. This work, which complements a previous static same systems, has been performed temperatures ranging from $20\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ to close below glass transitions. The data are analyzed within framework Rice-Ruina state- and rate-dependent model. show that this phenomenology is...
Associating collagen with biodegradable hydrophobic polyesters constitutes a promising method for the design of medicated biomaterials. Current collagen-polyester composite hydrogels consisting pre-formed polymeric particles encapsulated within low concentrated hydrogel suffer from poor physical properties and drug loading. Herein, an amphiphilic platform associating dense up to 50 wt% different hydrophobicity chain length is developed. An original fabrication disclosed based on in situ...
The rate dependence of fracture has been studied in a series physically associating triblock copolymer gels that have well-defined molecular structure. Compressive experiments were performed to develop strain energy function accurately captures the hardening behavior these materials. This same was utilized finite element model crack tip stresses, which become highly anisotropic at stress values below failure strength gels. release rate, G, is independent gel concentration when G normalized...
We present experimental evidence of self-healing shear cracks at a gel/glass interface. This system exhibits two dynamical regimes depending on the driving velocity: steady sliding high velocity $(>{V}_{\mathrm{c}}\ensuremath{\simeq}100--125\ensuremath{\mu}\mathrm{m}/\mathrm{s})$, characterized by shear-thinning rheology, and periodic stick-slip dynamics low velocity. In this last regime, slip occurs propagation pulses that restick via ``healing instability'' occurring when local reaches...
The macroscopic multicontact between two rough nominally flat surfaces is a common object whose physics only partially understood. This paper aimed at giving experimental evidence for the linear elastic response of interface to moderate shear force, i.e. below threshold incipient sliding. Non–intuitive properties interfacial stiffness are exhibited, in spirit friction laws, which should be practical interest when evaluating performances built–up system. These explained qualitively within...
We perform an experimental study of the amplitude and frequency shift stick-slip (SS) oscillations a paper-on-paper block spring system close to SS--steady-sliding Hopf bifurcation. The confrontation results with weakly nonlinear analytical analysis dynamics direct numerical calculations yields very satisfactory agreement model creep-controlled dry friction proposed by Heslot et al. [Phys. Rev. E 49, 4973 (1994)].
We study the shear response of a sliding multicontact interface submitted to harmonically modulated normal load, without loss contact. measure, at low velocities (V<100 &mgr;m s(-1)), average value &Fmacr; friction force and amplitude its first second harmonic components. The excitation frequency (f=120 Hz) is chosen much larger than natural one, associated with dynamical aging interface. show following: (i) In agreement engineering thumb rule, even modest modulation induces substantial...
Experiments of phase separation have been performed in a density-matched liquid mixture (partially deuterated cyclohexane-methanol at 1.4% below critical concentration) and pure fluid (${\mathrm{SF}}_{6}$ 3.6% above density). The usual strong gravity-induced flows that accompany fluids are suppressed by performing experiments under reduced gravity. microgravity compared with on Earth. Phase gravity is characterized pattern tightly packed droplets the minority whose growth can be expressed...
We measure the elastic and dissipative responses of a multi‐contact interface, formed between rough surfaces two contacting macroscopic solids, submitted to biased oscillating shear force. evidence that, beyond linear viscoelastic regime, observed at low amplitude, interface response exhibits component that corresponds onset frictional dissipation. The latter regime exists, whereas tangential force applied, far from nominal static threshold, does not provoke any sliding. This result, akin...
The full 2D analysis of roughness profiles fracture surfaces resulting from quasistatic crack propagation in gelatin gels reveals an original behavior characterized by (i) strong anisotropy with maximum at $V$-independent symmetry-preserving angles and (ii) a subcritical instability leading, below critical velocity, to cross-hatched regime due straight macrosteps drifting the same magic nucleated on crack-pinning network inhomogeneities. Step height values are determined width...
We study the effect of nonbinding Na+ ions on kinetics rupture alginate gels cross-linked by Ca2+. Wetting a crack tip with saline solution at physiological concentrations is found to be able induce quasi-instantaneous, 10-fold velocity jump. This analyzed phenomenological model for rate-dependent fracture energy in physical gels, extended here account role rate cross-link "unzipping". Ionic interaction act cooperatively mechanical tension, leading an enhanced rupture. The turns out second...
This paper presents the stability analysis of a system sliding at low velocities (<100 μm⋅s−1) under periodically modulated normal load, preserving interfacial contact. Experiments clearly evidence that vibrations generally stabilize against stick-slip oscillations, least for modulation frequency much larger than one. The mechanical model L. Bureau, T. Baumberger, and C. Caroli validated on steady-state response system, is used to map its diagram. takes explicitly into account finite...
We report on rate-dependent fracture energy measurements over three decades of steady crack velocities in alginate and gelatin hydrogels. evidence that irrespective gel thermoreversibility, thermally activated "unzipping" the noncovalent cross-link zones results slow propagation, prevailing against toughening effect viscous solvent drag during chain pull-out, which becomes efficient above a few mm s(-1). extend previous model [T. Baumberger et al., Nat. Mater. 5, 552 (2006)] to account for...
We show that the aging of mechanical relaxation a gelatin gel exhibits same scaling phenomenology as polymer and colloidal glasses. Besides, is known to exhibit logarithmic structural (stiffening). find stress accelerates this process. However, effect definitely irreducible mere age shift with respect natural aging. suggest it interpretable in terms elastically-aided elementary (coil$\to$helix) local events whose dynamics gradually slows down increases geometric frustration.
Syneresis of alginate hydrogels is accounted for by a closed-loop mechanism coupling network collapse events with the global solvent flow.