A5100766333- Advanced Materials and Mechanics
- Structural Analysis and Optimization
- Adhesion, Friction, and Surface Interactions
- Granular flow and fluidized beds
- Composite Structure Analysis and Optimization
- Advanced Sensor and Energy Harvesting Materials
- Vibration Control and Rheological Fluids
- Micro and Nano Robotics
- Fluid Dynamics and Vibration Analysis
- Dynamics and Control of Mechanical Systems
- Force Microscopy Techniques and Applications
- Pickering emulsions and particle stabilization
- Geotechnical and Geomechanical Engineering
- Tribology and Lubrication Engineering
- Biomimetic flight and propulsion mechanisms
- Fluid Dynamics and Turbulent Flows
- Fluid Dynamics Simulations and Interactions
- Surface Modification and Superhydrophobicity
- Advanced Theoretical and Applied Studies in Material Sciences and Geometry
- Vibration and Dynamic Analysis
- Cellular Mechanics and Interactions
- Modular Robots and Swarm Intelligence
- Enzyme Catalysis and Immobilization
- Archaeological and Historical Studies
- Fluid Dynamics and Thin Films
École Polytechnique Fédérale de Lausanne
2018-2025
ANA Aeroportos de Portugal (Portugal)
2013-2020
Massachusetts Institute of Technology
2010-2020
Flex (Mauritius)
2019-2020
Fernando Pessoa University
2017
IIT@MIT
2010-2011
Nestlé (Brazil)
2008
City College of New York
2007-2008
Chalmers University of Technology
2007-2008
Nestlé (Switzerland)
2007-2008
Negative Poisson's ratio behavior has been uncovered in cellular solids that comprise a solid matrix with square array of circular voids. The simplicity the fabrication implies robust behavior, which is relevant over range scales. results from an elastic instability, induces pattern transformation and excellent quantitative agreement found between calculation experiment.
The wrinkling and delamination of stiff thin films adhered to a polymer substrate have important applications in "flexible electronics." resulting periodic structures, when used for circuitry, remarkable mechanical properties because stretching or twisting the is mostly accommodated through bending film, which minimizes fatigue fracture. To date, this context patterning create an anisotropic substrate-film adhesion energy, thereby producing controlled array "blisters." However, even absence...
We introduce a class of continuum shell structures, the Buckliball, which undergoes structural transformation induced by buckling under pressure loading. The geometry Buckliball comprises spherical patterned with regular array circular voids. In order for pattern to be buckling, possible number and arrangement these voids are found restricted five specific configurations. Below critical internal pressure, narrow ligaments between buckle, leading cooperative cascade skeleton ball. This...
We experimentally investigate the crystallization of a uniformly heated quasi-2D granular fluid as function filling fraction. Our experimental results for Lindemann melting criterion, radial distribution function, bond order parameter, and statistics topological changes at particle level are same those found in simulations equilibrium hard disks. This direct mapping suggests that study systems can be effectively applied to nonequilibrium steady states such our driven dissipative system.
We report an experimental investigation of the caging motion in a uniformly heated granular fluid, for wide range filling fractions, $\phi$. At low $\phi$ classic diffusive behavior fluid is observed. However, as increased, temporary cages develop and particles become increasingly trapped by their neighbors. statistically analyze particle trajectories observe number robust features typically associated with dense molecular liquids colloids. Even though our monodisperse quasi-2D system known...
We study the effect of a dimplelike geometric imperfection on critical buckling load spherical elastic shells under pressure loading. This investigation combines precision experiments, finite element modeling, and numerical solutions reduced shell theory, all which are found to be in excellent quantitative agreement. In geometry magnitude defect can designed precisely fabricated through customizable rapid prototyping technique. Our primary focus is predictively describing sensitivity provide...
Abstract Graphene is a truly two‐dimensional atomic crystal with exceptional electronic and mechanical properties. Whereas conventional bulk thin‐film materials have been studied extensively, the key properties of graphene, such as tearing cracking, remain unknown, partly due to its nature ultimate single‐atom‐layer thickness, which result in breakdown material models. By combining first‐principles ReaxFF molecular dynamics experimental studies, bottom‐up investigation graphene sheets from...
We present results of a hybrid experimental and theoretical investigation the fracture scaling in scratch tests show that scratching is dominated process. Validated for paraffin wax, cement paste, Jurassic limestone steel, we derive model provides quantitative means to relate quantities measured properties materials at multiple scales. The scalability different probes depths opens new venues towards miniaturization our technique, extract even smaller length
Smart Morphable Surfaces enable switchable and tunable aerodynamic drag reduction of bluff bodies. Their topography, resembling the morphology golf balls, can be custom-generated through a wrinkling instability on curved surface. Pneumatic actuation these patterns results in control coefficient spherical samples by up to factor two, over range flow conditions. As service our authors readers, this journal provides supporting information supplied authors. Such materials are peer reviewed may...
Abstract Various manufacturing techniques exist to produce double-curvature shells, including injection, rotational and blow molding, as well dip coating. However, these industrial processes are typically geared for mass production not directly applicable laboratory research settings, where adaptable, inexpensive predictable prototyping tools desirable. Here, we study the rapid fabrication of hemispherical elastic shells by coating a curved surface with polymer solution that yields nearly...
Magneto-rheological elastomers (MREs) are functional materials that can be actuated by applying an external magnetic field. MREs comprise a composite of hard particles dispersed into nonmagnetic elastomeric matrix. By strong field, one magnetize the structure to program its deformation under subsequent application Hard MREs, whose coercivities large, have been receiving particular attention because programmed magnetization remains unchanged upon actuation. Hence, once made MRE is magnetized,...
Thin beams made of magnetorheological elastomers embedded with hard-magnetic particles (hard-MREs) are capable large deflections under an applied magnetic field. We propose a comprehensive framework, comprising beam model and 3D finite element modeling (FEM), to describe the behavior hard-MRE both uniform constant gradient fields. First, based on Helmholtz free energy bulk (3D) hard-MREs, we perform dimensional reduction derive 1D description obtain equilibrium equation through variational...
We develop a reduced-order model for thin plates made of hard magnetorheological elastomers (hard-MREs), which are composed hard-magnetic particles embedded in polymeric matrix. First, we propose new magnetic potential, as an alternative to existing torque-based 3D continuum theory hard-MREs, obtained by reformulating the remnant magnetization deformed hard-MRE body. Specifically, magnetizations initial and current configurations related rotation tensor decomposed from deformation gradient,...
We investigate the mechanics of bistable, hard-magnetic, elastic beams, combining experiments, finite-element modelling (FEM) and a reduced-order theory. The beam is made hard magneto-rheological elastomer, comprising two segments with antiparallel magnetization along centreline, set into bistable curved configuration by imposing an end-to-end shortening. Reversible snapping possible between these stable states. First, we experimentally characterize critical field strength for onset...
Recent studies on magnetically hard, particle-filled magnetorheological elastomers (h-MREs) have revealed their stretch-independent magnetization response after full pre-magnetization. We discuss this phenomenon, focusing incompressible, isotropic, h-MREs. demonstrate that the fully dissipative model of Mukherjee et al. (2021) for arbitrary loads can be reduced, under physically consistent assumptions, to energetic Yan (2023), but not Zhao (2019). The latter two are valid small magnetic...
Abstract This is a roadmap article with multiple contributors on different aspects of embodying intelligence and computing in the mechanical domain functional materials structures. Overall, an IOP broad, multi-author review leaders field discussing latest developments, commissioned by editorial board. The intention here to cover various topics adaptive structural material systems mechano-intelligence overall roadmap, twelve sections total. These from devices systems, such as computational...
In the present study, we use a model gastro-intestinal system to study influence of different food-grade surface-active molecules (Sn-2 monopalmitin, beta-lactoglobulin, or lysophosphatodylcholine) on lipase activity. The interfacial activity and surfactants are assessed with pendant drop technique, commonly used tensiometry instrument. A mathematical is adopted which enables quantitative determination composition water-oil interface as function bulk surfactant concentration in mixtures. Our...
We present results from an experimental investigation of the indentation nonspherical pressurized elastic shells with a positive Gauss curvature. A predictive framework is proposed that rationalizes dependence local rigidity indented shell on curvature in neighborhood locus indentation, in-out pressure differential, and material properties. In our approach, we combine classic theory for spherical recent analytical developments case, proceed, most part, by analogy, guided own experiments. By...
We study the buckling of hemispherical elastic shells subjected to combined effect pressure loading and a probing force. perform an experimental investigation using thin nearly uniform thickness that are fabricated with well-controlled geometric imperfection. By systematically varying indentation displacement geometry probe, we probe-induced deflections have on strength our spherical shells. The results then compared finite element simulations, as well recent theoretical predictions from...