keywords : instability, interacting particles, turbulence, slender structure
Surface clustering in circular arenas
The cockroach robots are forming a gas phase at low densities. Even if their elongated shape should suggest an alignment in the bulk, this is not observed because two particles colliding will bounce back with non-parallel trajectories after the collision. For moderate densities, typically 10% in surface fraction, a surface cluster is observed with a spontaneous ordering of the robots perpendicularly to the walls.
Traffic jams with robots
The robots are circulating in a circular track mimicking a lane reduction. In half of the track, the particles are in single file motion and on the other half, the track is large enough to allow the overtaking. For the lowest densities, the traffic is free. At high densities, the traffic is jammed due to a clogging of the particle at the bottleneck. For intermediate densities, the traffic is intermittent and spontaneously transits between free and jammed states.
A slowing down of the particle is operated by a modification of the track surface. An improvement of the traffic near congestion is reported according to the “slower is faster” effect.
Spontaneous sorting of circling active particles
The cockroach robots can be modified to move in circular trajectories either clockwise or anti-clockwise. Two types of motions are observed : a first mode without boundary interaction and the particle moving in quasi circular trajectories and a second mode with boundary interaction and the particles captured and guided by the walls. The wall guiding is a one way motion that depends on the particle’s polarity.
The polar wall current is at the origin of a spontaneous sorting mechanism within a population with an equal number of clockwise and anti-clockwise elements.
Particle levitation in turbulent jets
Rotation of a chiral particle in levitation
The experiments are performed with an immerded water jet. A chiral particle is constructred by attaching a helical tail to a sphere. The chiral particle is buoyant and the jet is pointing downward (inverted levitation). The spinning velocity is proportional to the tail twist and an optimal length for the tail is found to maximize the rotation for a given twist.
This work was featured on the cover of Physics of Fluids in December 2019.
Levitation of a sphere in a double trap
Two vertical turbulent jets are used to levitate a ball. With symmetric flow rates, the particle is trapped on a fork structure, reminiscent of a pitchfork bifurcation. For asymmetric flow rates, the jet of higher flow rate may capture the ball after a cycle of flow rate.
This works show that it is possible to decide above which trap the sphere is capture only by acting on the flow rates without moving the nozzles.
Sedimentation of spherical particles falling non vertically
Transition paths of individual particles falling in viscosity-stratified fluid
A water mixture is prepared in a columnar tank so that the viscosity is continuously varied from a high a value at the free surface to a low value at the bottom of the tank. An individual particle falling in the stratified fluid overgoes a path transition from a vertical falling regime to a oblique settling regime in the lowest part of the tank. The consequences of fluid entrainment is discussed as the origin of a delay for the establishment of the oblique regime.
Columnar structures for dilute suspensions of particle falling in the oblique regime
A set of particles is released (glass beads, 2 mm) in a fluid at rest with a viscosity such a single particle would fall in the oblique regime. For a relativelly low particle concentration (volumic fraction 10-3 to 10-4), the particles organize in columnar structures. The origin of this collective behaviour is attributed to the particle-particle wake interactions whose statistical occurence is enhanced because of the non vertical exploration of the particles in the non-vertical regime.
Reconfiguration refers to the behaviour of deformable structures in high-velocity fluid flows. The main field of interest is botany as reconfiguration can be presented as a survival strategy adopted by plants not to be damaged in high winds (Lafontaine’s Le chêne et le roseau happens to be, beyond poetry, a very good introduction to the concept of reconfiguration).
An effective reconfiguration experiment with a rigid sphere trapped in a jet
If someone wants to let think that science is somehow magic, levitation is a good option. One can use for instance the turbulent jet of a hair dryer oriented upward to capture and manipulate a ping-pong ball. The fluid forces in a turbulent jet has some remarkable properties which makes that moving a sphere on the jet axis is somehow equivalent to change its size without moving it. This principle is used to build an analogy between the problem of a rigid sphere free to find an equilibrium position in a turbulent jet and the problem of an effective deformable sphere free to find its shape in a stationnary flow.
Reconfiguration in the constant drag regime
For a plant in the wind, the deformability makes that the relation between drag force F and velocity v is not the usual FR ~ v2 that would be measured for a rigid body (R). Actually, forces for soft objets (S) are found to obey a similar scaling relation where FS ~ v2-E where the exponant 2 is a reduced by a so called Vogel exponent E, that is typically of order 1 for soft elastic structure (plates, rod, leaves, branches, …). The outreach of this work was to show that it is possible to design a deformable structure for which the Vogel exponent equals 2 which means that the drag on the structure is independent of the flow velocity.
Elasticity of thin plates: curvature-induced rigidity
A thin elastic plate like a sheet of paper can be easily bent by its own weight. To avoid this situation, newspaper readers have developped a well-known trick (figure, imaget 1) that is to impose a transverse curvature to the newspaper sheet they are reading. The same trick is also observed in plants (figure, imaget 1) with leaves shaped as long strips (yucca, maize, …). In this work, a thin elastic strip has been pressed onto a curved frame. The curvature imposed by the clamping is smoothly decreasing and after a given distance, the ribbon is flat. In terms of mechanical properties, it means that the sheet is rigid with respect to bending in the curved region and soft and easily bent by gravity in the flat terminal portion.
Frequency-driving of mechanical resonators
Silicon carbide nanowires are used as mechanical resonators. The vibration modes are observed by the harmonic forcing for some specific frequencies. The forcing is coming from an oscillating electric field applied between the nanowire and a counter-electrode next to it. The mechanical damping has been specifically investigated and it was shown that the electric forcing scheme may introduce additionnal mechanical damping.
A self-oscillator may be presented as a device that generates an oscillating output from a continuous driving. If a strong electric field is applied to a silicon carbide nanowire, a significant DC current is estalished that may eventually lead to self-oscillation. This spontaneous oscillation is characterized by a mechanical oscillation and an oscillating AC component in the current at the same frequency selected by the electromechanical system.
A self-oscillator is a nonlinear system by principle since a nonzero-frequency emerges from a zero-frequency driving. If an additional external frequency forcing fe is imposed to a self-oscillator with frequency fo two situations are possible: either fe is too far from fo and the self-oscillator keeps its frequency fo, either fe is close enough and a synchronized state emerges where the self-oscillator adopts the frequency of the external driving fe.
Response to phase shift
Noise-induced phase jumps
- Nom : Thomas Barois
- Email : 405ab0990f21ddf85c8812e94704e7dc
- IdHAL : thomas-barois
Année de production
Équipes de recherche
Articles dans une revue
- Thomas Barois, Guillaume Ricard, Victor Champain, Lucas Gey, Hamid Kellay. The levitation of a sphere by two parallel turbulent jets. Physics of Fluids, American Institute of Physics, 2020, 32 (4), pp.045111. ⟨10.1063/5.0002955⟩. ⟨hal-02553316⟩
- Thomas Barois, Jean-François Boudet, Juho Lintuvuori, Hamid Kellay. Sorting and Extraction of Self-Propelled Chiral Particles by Polarized Wall Currents. Physical Review Letters, American Physical Society, 2020, 125 (23), pp.238003. ⟨10.1103/PhysRevLett.125.238003⟩. ⟨hal-03036916⟩
- Thomas Barois, Peter Huck, Charles Paleo, Mickaël Bourgoin, Romain Volk. Probing fluid torque with a hydrodynamical trap: Rotation of chiral particles levitating in a turbulent jet. Physics of Fluids, American Institute of Physics, 2019, 31 (12), pp.125116. ⟨10.1063/1.5131207⟩. ⟨hal-02427609⟩
- Thomas Barois, Jean-François Boudet, Nicolas Lanchon, Juho Lintuvuori, Hamid Kellay. Characterization and control of a bottleneck-induced traffic-jam transition for self-propelled particles in a track. Physical Review E , American Physical Society (APS), 2019, 99 (5), pp.052605 (1-9). ⟨10.1103/PhysRevE.99.052605⟩. ⟨hal-02129176⟩
- Mickaël Bourgoin, Christophe Baudet, S. Kharche, Nicolas Mordant, Tristan Vandenberghe, et al.. Investigation of the small-scale statistics of turbulence in the Modane S1MA wind tunnel. CEAS Aeronautical Journal, Springer, 2018, 9 (2), pp.269-281. ⟨10.1007/s13272-017-0254-3⟩. ⟨hal-01578798⟩
- Antoine Deblais, Thomas Barois, T. Guérin, Pierre-Henri Delville, Rémi Vaudaine, et al.. Boundaries Control Collective Dynamics of Inertial Self-Propelled Robots. Physical Review Letters, American Physical Society, 2018, 120 (18), pp.188002 (1-5). ⟨10.1103/PhysRevLett.120.188002⟩. ⟨hal-01792275⟩
- Thomas Barois, P. D. Huck, M. Bourgoin, Romain Volk. Equilibrium position of a rigid sphere in a turbulent jet: A problem of elastic reconfiguration. Physical Review E , American Physical Society (APS), 2017, 96 (3), pp.33105 (1-5). ⟨10.1103/PhysRevE.96.033105⟩. ⟨hal-01598389⟩
- Sander G. Huisman, Thomas Barois, Mickaël Bourgoin, Agathe Chouippe, Todor Doychev, et al.. Columnar structure formation of a dilute suspension of settling spherical particles in a quiescent fluid. Physical Review Fluids, American Physical Society, 2016, 1 (7), pp.74204. ⟨10.1103/PhysRevFluids.1.074204⟩. ⟨hal-01565116⟩
- T Barois, Sorin Perisanu, Philippe Poncharal, Pascal Vincent, Stephen T. Purcell, et al.. Quality factor enhancement of Nanoelectromechanical systems by capacitive driving beyond the resonance. Physical Review Applied, American Physical Society, 2016, 6 (1), pp.014012. ⟨10.1103/PhysRevApplied.6.014012⟩. ⟨hal-01330827⟩
- Thomas Barois, Sorin Perisanu, Philippe Poncharal, Pascal Vincent, S. T. Purcell, et al.. Quality-Factor Enhancement of Nanoelectromechanical Systems by Capacitive Driving Beyond Resonance. Physical Review Applied, American Physical Society, 2016, 6, pp.014012. ⟨10.1103/PhysRevApplied.6.014012⟩. ⟨hal-02304934⟩
- Thomas Barois, Loïc Tadrist, Catherine Quilliet, Yoël Forterre. How a Curved Elastic Strip Opens. Physical Review Letters, American Physical Society, 2014, 113 (21), ⟨10.1103/PhysRevLett.113.214301⟩. ⟨hal-01431992⟩
- Thomas Barois, S. Perisanu, Pascal Vincent, Stephen T. Purcell, Anthony Ayari. Frequency modulated self-oscillation and phase inertia in a synchronized nanowire mechanical resonator. New Journal of Physics, Institute of Physics: Open Access Journals, 2014, 16, pp.083009. ⟨10.1088/1367-2630/16/8/083009⟩. ⟨hal-01058248⟩
- Thomas Barois, S. Perisanu, Anthony Ayari, Stephen T. Purcell, Pascal Vincent. Role of fluctuations and nonlinearities on field emission nanomechanical self-oscillators. Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2013, 88, pp.195428. ⟨10.1103/PhysRevB.88.195428⟩. ⟨hal-00917398⟩
- Thomas Barois, Emmanuel de Langre. Flexible body with drag independent of the flow velocity. Journal of Fluid Mechanics, Cambridge University Press (CUP), 2013, 735, pp.R2. ⟨10.1017/jfm.2013.516⟩. ⟨hal-00995147⟩
- Thomas Barois, Anthony Ayari, P. Vincent, S. Perisanu, P. Poncharal, et al.. Ultra Low Power Consumption for Self-Oscillating Nanoelectromechanical Systems Constructed by Contacting Two Nanowires. Nano Letters, American Chemical Society, 2013, 13 (4), pp.1451-1456. ⟨10.1021/nl304352w⟩. ⟨hal-01565117⟩
- Alessandro Siria, Thomas Barois, Kenny Vilella, Sorin Perisanu, Anthony Ayari, et al.. Electron Fluctuation Induced Resonance Broadening in Nano Electromechanical Systems: The Origin of Shear Force in Vacuum. Nano Letters, American Chemical Society, 2012, 12 (7), pp.3551-3556. ⟨10.1021/nl301618p⟩. ⟨hal-01565118⟩
- Thomas Barois, A. Ayari, A. Siria, S. Perisanu, P. Vincent, et al.. Ohmic electromechanical dissipation in nanomechanical cantilevers. Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2012, 85 (7), pp.075407. ⟨10.1103/PhysRevB.85.075407⟩. ⟨hal-01565120⟩
- Pascal Vincent, Anthony Ayari, Philippe Poncharal, Thomas Barois, Sorin Perisanu, et al.. Carbon nanotube nanoradios: The field emission and transistor configurations. Comptes Rendus Physique, Centre Mersenne, 2012, 13 (5), pp.395-409. ⟨10.1016/j.crhy.2012.01.003⟩. ⟨hal-01565119⟩
- S. Perisanu, Thomas Barois, P. Poncharal, T. Gaillard, A. Ayari, et al.. The mechanical resonances of electrostatically coupled nanocantilevers. Applied Physics Letters, American Institute of Physics, 2011, 98 (6), pp.063110. ⟨10.1063/1.3553779⟩. ⟨hal-01565121⟩
- P. Vincent, P. Poncharal, T. Barois, S. Perisanu, V. Gouttenoire, et al.. Performance of field-emitting resonating carbon nanotubes as radio-frequency demodulators. Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2011, 83 (15), pp.155446. ⟨10.1103/physrevb.83.155446⟩. ⟨hal-00997993⟩
- Vincent Gouttenoire, Thomas Barois, Sorin-Mihai Perisanu, Jean -Louis Leclercq, S.T. Purcell, et al.. Digital and FM demodulation of a doubly-clamped single wall carbon nanotube oscillator: towards a nanotube cell phone. Small, Wiley-VCH Verlag, 2010, 6 (9), pp.1060. ⟨10.1002/smll.200901984⟩. ⟨hal-00484479⟩
- S. Perisanu, Thomas Barois, A. Ayari, P. Poncharal, M. Choueib, et al.. Beyond the linear and Duffing regimes in nanomechanics: Circularly polarized mechanical resonances of nanocantilevers. Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2010, 81 (16), pp.165440. ⟨10.1103/PhysRevB.81.165440⟩. ⟨hal-01565122⟩
- Arnaud Lazarus, T. Barois, S. Perisanu, P. Poncharal, Paul Manneville, et al.. Simple modeling of self-oscillations in nanoelectromechanical systems. Applied Physics Letters, American Institute of Physics, 2010, 96 (19), pp.193114. ⟨10.1063/1.3396191⟩. ⟨hal-01021117⟩
Communications dans un congrès
- Pascal Vincent, Anthony Ayari, Sorin Perisanu, Philippe Poncharal, Thomas Barois, et al.. Field Emission as a tool for Exploring New Phenemena in Nanomechanics. International Vacuum Nanoelectronics Conference (IVNC), Jul 2015, Guangzhou, China. pp.2-2, ⟨10.1109/IVNC.2015.7225366⟩. ⟨hal-01565125⟩
- Anthony Ayari, Thomas Barois, Sorin Perisanu, Pascal Vincent, Stephen Purcell. Synchronization of nanowire self-oscillators. General Assembly and Scientific Symposium (URSI GASS), 2014 XXXIth URSI, Aug 2014, Beijing, China. ⟨10.1109/URSIGASS.2014.6929481⟩. ⟨hal-01565126⟩
- Thomas Barois, Sorin Perisanu, Philippe Poncharal, Pascal Vincent, Stephen Purcell, et al.. Signal amplification in a synchronized field emission NEMS. 2012 International Conference on Electromagnetics in Advanced Applications (ICEAA), Sep 2012, Cape Town, South Africa. pp.551-553, ⟨10.1109/ICEAA.2012.6328688⟩. ⟨hal-01565127⟩
Thomas Barois, Peter D. Huck, Mickaël Bourgoin, Romain Volk
Physical Review E PDF
Investigation of the small-scale statistics of turbulence in the Modane S1MA wind tunnel
M Bourgoin, C Baudet, S Kharche, N Mordant, T Vandenberghe, S Sumbekova, N Stelzenmuller, A Aliseda, M Gibert, P-E Roche, R Volk, T Barois, M Lopez Caballero, L Chevillard, J-F Pinton, L Fiabane, J Delville, C Fourment, A Bouha, L Danaila, E Bodenschatz, G Bewley, M Sinhuber, A Segalini, R Örlü, I Torrano, J Mantik, D Guariglia, V Uruba, V Skala, J Puczylowski, J Peinke
CEAS Aeronautical Journal PDF
Sander Huisman, Thomas Barois, Mickaël Bourgoin, Agathe Chouippe, Todor Doychev, Peter Huck, Carla Bello Morales, Markus Uhlmann, and Romain Volk
Physical Review Fluids PDF
Quality-Factor Enhancement of Nanoelectromechanical Systems by Capacitive Driving Beyond Resonance
Thomas Barois, Sorin Perisanu, Philippe Poncharal, Philippe Vincent, Stephen Purcell, and Anthony Ayari
Physical Review Applied PDF
Thomas Barois, Loïc Tadrist, Catherine Quilliet, and Yoël Forterre
Physical Review Letters PDF
Frequency modulated self-oscillation and phase inertia in a synchronized nanowire mechanical resonator
Thomas Barois, Sorin Perisanu, Philippe Vincent, Stephen Purcell, and Anthony Ayari
New Journal of Physics PDF
Thomas Barois, Sorin Perisanu, Philippe Vincent, Stephen Purcell, and Anthony Ayari
Physical Review B PDF
Flexible body with drag independent of the flow velocity
Thomas Barois and Emmanuel de Langre
Journal of Fluid Mechanics PDF
Ultra Low Power Consumption for Self-Oscillating Nanoelectromechanical Systems Constructed by Contacting Two Nanowires
Thomas Barois, Anthony Ayari, Pascal Vincent, Sorin Perisanu, Philippe Poncharal, and Stephen Purcell
Pascal Vincent, Anthony Ayari, Philippe Poncharal, Thomas Barois, Sorin Perisanu, Vincent Gouttenoire, and Stephen Purcell
Comptes Rendus Physique PDF
Electron Fluctuation Induced Resonance Broadening in Nano Electromechanical Systems: The Origin of Shear Force in Vacuum
Alessandro Siria, Thomas Barois, Kenny Vilella, Sorin Perisanu, Anthony Ayari, Dominique Guillot, Stephen Purcell, and Philippe Poncharal
Ohmic electromechanical dissipation in nanomechanical cantilevers
Thomas Barois, Anthony Ayari, Alessandro Siria, Sorin Perisanu, Pascal Vincent, Philippe Poncharal, and Stephen Purcell
Physical Review B PDF
Pascal Vincent, Philippe Poncharal, Thomas Barois, Sorin Perisanu, Vincent Gouttenoire, Henri Frachon, Anthony Lazarus, Emmanuel de Langre, Eric Minoux, Mickaël Charles, Afshin Ziaei, Dominique Guillot, May Choueib, Anthony Ayari, and Stephen Purcell
Physical Review B PDF
The mechanical resonances of electrostatically coupled nanocantilevers
Sorin Perisanu, Thomas Barois, Philippe Poncharal, Thibaut Gaillard, Anthony Ayari, Stephen Purcell, and Pascal Vincent
Applied Physics Letters PDF
Arnaud Lazarus, Thomas Barois, Sorin Perisanu, Philippe Poncharal, Paul Manneville, Emmanuel de Langre, Stephen Purcell, Pascal Vincent, and Anthony Ayari
Applied Physics Letters PDF
Digital and FM Demodulation of a Doubly Clamped Single‐Walled Carbon‐Nanotube Oscillator: Towards a Nanotube Cell Phone
Vincent Gouttenoire, Thomas Barois, Sorin Perisanu, Jean‐Louis Leclercq, Stephen T Purcell, Pascal Vincent, and Anthony Ayari
Beyond the linear and Duffing regimes in nanomechanics: Circularly polarized mechanical resonances of nanocantilevers
Sorin Perisanu, Thomas Barois, Anthony Ayari, Philippe Poncharal, May Choueib, Stephen Purcell, and Pascal Vincent
Physical Review B PDF
Pascal Vincent, Anthony Ayari, Sorin Perisanu, Philippe Poncharal, Thomas Barois, Arnaud Derouet, May Choueib, Stephen Purcell
Vacuum Nanoelectronics Conference (IVNC), 2015 28th International
Anthony Ayari, Thomas Barois, Sorin Perisanu, Pascal Vincent, and Stephen Purcell
General Assembly and Scientific Symposium (URSI GASS), 2014 XXXIth URSI
Thomas Barois, Sorin Perisanu, Philippe Poncharal, Pascal Vincent, Stephen Purcell, Anthony Ayari
2012 International Conference on Electromagnetics in Advanced Applications
– Consonance, dissonance et distances (main speaker: Nicolas Trottignon), Séminaire détente mathématique – Maison de l’Informatique et des Mathématiques, Fev. 2016, Lyon.
– The mechanics of plants: what we can learn from thin elastic strips (MSC Paris Diderot, Mar. 2015 – IPR Rennes, April 2015- IMFT Toulouse, April 2015 – LOMA, May 2015 – ILM Lyon, Dec. 2015 – Univ. Liège, Apr. 2016).
– Experimental Investigation of Small-Scale Homogeneous Isotropic Turbulence in S1MA wind tunnel – CEAS 2015, Delft TU.
– Flexible body with drag independent of the flow velocity – APS-DFD Meeting Pittsburgh, Nov. 2013.
– Nanomechanics of carbon nanotubes: an excitation technique based on telecommunication signals – Trans’Alp nano, Como, Italy, May 2010.
– Detection of mechanical resonances of doubly-clamped carbon nanotubes by FM techniques (poster) – GDR Nanotubes & Graphene – Coma ruga, Spain, Sept. 2009.
– Investigation of small scale turbulence in equipments designed for aircrafts testing – ENS Lyon Sept 2015.
– The shape of thin things: experiments with elastic, plastic, and viscous systems – Laboratoire Écoulement Géophysiques et Industriels, Grenoble, Apr. 2014.
– Drag reduction: a flexible body with drag independent of the flow velocity – Laboratoire Écoulement Géophysiques et Industriels, Grenoble, Oct. 2013.
Anthony Ayari, Pascal Vincent, Sorin Perisanu, Philippe Poncharal, Stephen Purcell (ILM, Lyon)
Emmanuel de Langre (LadHyX, Palaiseau)
Loïc Tadrist (Microfluidics Lab, Univ. Liège)
Catherine Quilliet (Liphy, Grenoble)
Yoël Forterre (IUSTI, Marseille)
Nicolas Mordant (LEGI, Univ. Grenoble)
Mathieu Gibert (Institut Néel, Grenoble)
Mickaël Bourgoin, Romain Volk, Peter Huck, Sander Huisman (Lab. physique, ENS Lyon)
Markus Uhlmann, Agathe Chouippe (KIT, Karlsruhe)
Yvan Dossmann (LEMTA, Univ. Nancy)
since 2016: Permanent researcher at LOMA (CR2/CNRS)
2014 – 2016 : Postdoc Laboratoire de Physique (ENS Lyon)
2013 – 2014 : Postdoc LEGI (Grenoble)
2012 – 2013 : Postdoc LadHyX (Palaiseau)
2009 – 2012 : PhD student LPMCN (now ILM) (Univ. Lyon 1)
Education & Internships
2008 : Agrégation de Physique
2007 : Internship, Univ. de Chile, Santiago de Chile
2006 : Internship, Lab. Of the Future (Pessac)
2005 – 2008 : Studentship at École Normale Supérieure (Lyon)
Laboratoire Ondes et Matière d’Aquitaine (LOMA)
351 cours de la libération
33405 Talence Cedex
Phone : + 33 (0)5 40 00 6508