Florent Malloggi | CEA - Academia.edu (original) (raw)

Papers by Florent Malloggi

International audienceWe present a new route for the fabrication of highly specialized micro-capi... more International audienceWe present a new route for the fabrication of highly specialized micro-capillaries, based on the phenomenon of thin polymer films self-rolling. Before rolling, the surface can be patterned (chemically, topographically), permitting the fabrication of inexpensive fully functionalized capillaries

Lecture Notes in Physics, 2015

Microfluidics is the science and technology of systems that process or manipulate small amounts o... more Microfluidics is the science and technology of systems that process or manipulate small amounts of fluids using channels with dimensions of one to hundreds of micrometers. This field is mainly driven by technological applications where the aim is to develop entire laboratories inside chips. Introduced more than a decade ago, microfluidics has quickly become an important tool in several fields including new technologies as well as basic research. One reason for its fast development is based on the predictability of the flows at such scale and the exquisite control of interfaces in microchannels. Nowadays microfluidics has a place in many scientific fields. More often it is seen as a tool for the development of various topics related to chemistry, biology or physics. The list of possible applications and developed systems is very long and it is not the purpose of this chapter. In the following, we focus on the physics foundations on which this discipline relies. After a brief introduction on lab on chip technology, we introduce the basis of fluid mechanics with the governing equation for a fluid in motion. We also introduce diffusion transport and capillary effects which are dominant in microfluidic systems. Throughout the chapter we will illustrate the basic principles with practical examples.

Physical Review E, 2008

We study the rheology of sheared granular flows close to a jamming transition. We use the approac... more We study the rheology of sheared granular flows close to a jamming transition. We use the approach of partially fluidized theory ͑PFT͒ with a full set of equations extending the thin layer approximation derived previously for the description of the granular avalanches phenomenology. This theory provides a picture compatible with a local rheology at large shear rates ͓G. D. R. Midi, Eur. Phys. J. E 14, 341 ͑2004͔͒ and it works in the vicinity of the jamming transition, where a description in terms of a simple local rheology comes short. We investigate two situations displaying important deviations from local rheology. The first one is based on a set of numerical simulations of sheared soft two-dimensional circular grains. The next case describes previous experimental results obtained on avalanches of sandy material flowing down an incline. Both cases display, close to jamming, significant deviations from the now standard Pouliquen's flow rule ͓O. Pouliquen, Phys. Fluids 11, 542 ͑1999͒; 11, 1956 ͑1999͔͒. This discrepancy is the hallmark of a strongly nonlocal rheology and in both cases, we relate the empirical results and the outcomes of PFT. The numerical simulations show a characteristic constitutive structure for the fluid part of the stress involving the confining pressure and the material stiffness that appear in the form of an additional dimensionless parameter. This constitutive relation is then used to describe the case of sandy flows. We show a quantitative agreement as far as the effective flow rules are concerned. A fundamental feature is identified in PFT as the existence of a jammed layer developing in the vicinity of the flow arrest that corroborates the experimental findings. Finally, we study the case of solitary erosive granular avalanches and relate the outcome with the PFT analysis.

Lab on a Chip, 2013

We propose a microfluidics device whose main functional part consists of a microcapillary produce... more We propose a microfluidics device whose main functional part consists of a microcapillary produced by the self-rolling of a thin poly(dimethylsiloxane) film. Rolling is caused by inhomogeneous swelling of the film, pre-treated by oxygen plasma, in the vapour of chloroform. The capillaries are integrated with external electrical circuits by co-rolling electrodes and micro-resistors. The local control of temperature in the tubes by Joule heating is illustrated via the rate of an intra-tubular chemiluminescent reaction. The novel tubes with engineered inner structure can find numerous advanced applications such as functional elements of integrated microfluidics circuits.

We present a new route for the fabrication of highly specialized micro-capillaries, based on the ... more We present a new route for the fabrication of highly specialized micro-capillaries, based on the phenomenon of thin polymer films self-rolling. Before rolling, the surface can be patterned (chemically, topographically), permitting the fabrication of inexpensive fully functionalized capillaries. Spontaneous curvature is a well-known instability [1] which occurs in films with gradients of stress along the normal axis. Recently, this effect was used to fabricate tubes as a self-assembly process [2]. We focus on the application of those self-rolled microsystems to lab-on-chip technology. We propose methods to induce the spontaneous rolling of polymeric films, more precisely polydimethylsiloxane (PDMS). The advantage of such system is threefold: i-Those systems are inexpensive to design. ii-The inner surface of the capillary is accessible before rolling and can be properly functionalized and characterized. iii-The formation of the channel itself is not a lithographic process. The fabrica...

This review presents an overview of the different techniques developed over the last decade to re... more This review presents an overview of the different techniques developed over the last decade to regulate the temperature within microfluidic systems. A variety of different approaches has been adopted, from external heating sources to Joule heating, microwaves or the use of lasers to cite just a few examples. The scope of the technical solutions developed to date is impressive and encompasses for instance temperature ramp rates ranging from 0.1 to 2,000 °C/s leading to homogeneous temperatures from −3 °C to 120 °C, and constant gradients from 6 to 40 °C/mm with a fair degree of accuracy. We also examine some recent strategies developed for applications such as digital microfluidics, where integration of a heating source to generate a temperature gradient offers control of a key parameter, without necessarily requiring great accuracy. Conversely, Temperature Gradient Focusing requires high accuracy in order to control both the concentration and separation of charged species. In addition, the Polymerase Chain Reaction requires both accuracy (homogeneous temperature) and integration to carry out demanding heating cycles. The spectrum of applications requiring temperature regulation is growing rapidly with increasingly important implications for the physical, chemical and biotechnological sectors, depending on the relevant heating technique.

Journal of Colloid and Interface Science

arXiv: Soft Condensed Matter, 2014

Recent progress in colloidal science has led to elaborate self-assembled structures whose complex... more Recent progress in colloidal science has led to elaborate self-assembled structures whose complexity raises hopes for elaborating new materials. However, the throughputs are extremely low and consequently, the chance to produce materials of industrial interest, for instance, groundbreaking optical devices, harnessing complete three-dimensional band gaps, is markedly low. We discovered a novel hydrodynamic effect that may unlock this bottleneck. It is based on the dipolar flow interactions that build up when droplets are slowed down by the microchannel walls along which they are transported. Coupled with depletion forces, we succeeded to form, via a continuous flow process, at unprecedented speeds and under exquisite control, a rich ensemble of monodisperse planar and tridimensional clusters, such as chains, triangles, diamonds, tetahedrons, heterotrimers, possessing geometrical, chemical, and/or magnetic anisotropies enabling directional bonding. Continuous productions of millions o...

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Self-rolled polymer film: a promising route to microfluidic devices Rémy Brossard, Baptiste Sarrazin, Patrick Guenoun, Florent Malloggi

We report on the development of a PDMS microdevice integrating a magnetic chamber dedicated to ma... more We report on the development of a PDMS microdevice integrating a magnetic chamber dedicated to magnetic nanoparticles trapping / release. This magnetic chamber consists in ferromagnetic iron beads, packed by a physical restriction, that present the capability of concentrating magnetic field lines from external permanent magnet. It results an enhanced magnetic flux density and therefore high magnetic force within the magnetic chamber. The microdevice has been characterized with finite element numerical simulation and fluorescent microscope imaging. Setting the flow rate at 100 μl/h, nanoparticles enrichment about 4000-fold has been achieved with a trapping / release sequence of a few seconds.

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Ions at interfaces: accessing the first nanometers using X-ray standing waves Soumaya Ben-Jabrallah, Florent Malloggi, Luc Belloni, Luc Girard, Dmitri Novikov, Cristian Mocuta, Dominique Thiaudière, Jean Daillant,

We report on the development of a microdevice dedicated to allergy diagnosis which combines both ... more We report on the development of a microdevice dedicated to allergy diagnosis which combines both the advantages of homogeneous and heterogeneous immunoassays (IAs). As allergy diagnosis is based on IgE quantitation, we have used magnetic core shell nanoparticles (MCSNPs) as IgE capture nanoplateform. Integrating such immunosupport allows to perform the target antibody (IgE) capture in colloidal phase and thus to increase the IgE capture kinetics. Moreover, due to their magnetic properties and to the magnetic trap we have previously developed, the MCSNPs and therefore the target will be confined and preconcentrated prior the detection step. This microfluidic approach has been successfully developed for allergy diagnosis. The assay time was 20 min with a IgE limit of detection of 1 ng/mL.

In recent years, microfluidic-based sample preparation techniques have emerged as a powerful tool... more In recent years, microfluidic-based sample preparation techniques have emerged as a powerful tool for measurements at large scale X-ray facilities. Most often the microfluidic device was a form of hybrid system, i.e. an assembly of different materials, because a simple, versatile and inexpensive microfabrication method, on the one hand, and X-ray compatibility, on the other hand, cannot generally be achieved by the same material. The arrival of a new polymer family based on off-stoichiometric thiol-ene-epoxy (OSTE+) has recently redistributed the cards. In this context, we studied the relevance and the compatibility of OSTE+ for small-angle X-ray scattering (SAXS) studies. The material was characterized regarding its X-ray properties (transmission coefficient, attenuation coefficient, scattering pattern and polymer aging under X-ray light) and their comparison with those of the usual polymers used in microfluidics and/or for synchrotron radiation experiments. We show that OSTE+ has ...

Langmuir, 2008

We study the detachment of conductive aqueous drops in ambient oil from an electrode in the prese... more We study the detachment of conductive aqueous drops in ambient oil from an electrode in the presence of ac electric fields. Making use of the electrowetting effect, we determine the charge of the detached sessile drops. Drops are found to be discharged at high ac frequency in line with earlier predictions. At low frequencies, we find a wide but unexpected charge distribution displaying a frequency-dependent nonzero minimum charge. This observation is explained in terms of the stabilization of capillary bridges in electric fields, which prevents the hydrodynamic pinch-off for certain phases of the ac field.

Lab on a Chip

We present an innovative microfluidic-based system that automatizes the mutation accumulation cul... more We present an innovative microfluidic-based system that automatizes the mutation accumulation culture in budding yeast. We speed up by one order of magnitude the time necessary for genome-wide measurements of mutational profiles.

Lab on a chip, 2011

Magnetic core shell nanoparticles (MCSNPs) 30 nm diameter with a magnetic weight of 10% are usual... more Magnetic core shell nanoparticles (MCSNPs) 30 nm diameter with a magnetic weight of 10% are usually much too small to be trapped in microfluidic systems using classical external magnets. Here, a simple microchip for efficient MCSNPs trapping and release is presented. It comprises a bed of micrometric iron beads (6-8 μm diameter) packed in a microchannel against a physical restriction and presenting a low dead volume of 0.8 nL. These beads of high magnetic permeability are used to focus magnetic field lines from an external permanent magnet and generate local high magnetic gradients. The nanoparticles magnetic trap has been characterised both by numerical simulations and fluorescent MCSNPs imaging. Numerical simulations have been performed to map both the magnetic flux density and the magnetic force, and showed that MCSNPs are preferentially trapped at the iron bead magnetic poles where the magnetic force is increased by 3 orders of magnitude. The trapping efficiency was experimental...

International audienceWe present a new route for the fabrication of highly specialized micro-capi... more International audienceWe present a new route for the fabrication of highly specialized micro-capillaries, based on the phenomenon of thin polymer films self-rolling. Before rolling, the surface can be patterned (chemically, topographically), permitting the fabrication of inexpensive fully functionalized capillaries

Lecture Notes in Physics, 2015

Microfluidics is the science and technology of systems that process or manipulate small amounts o... more Microfluidics is the science and technology of systems that process or manipulate small amounts of fluids using channels with dimensions of one to hundreds of micrometers. This field is mainly driven by technological applications where the aim is to develop entire laboratories inside chips. Introduced more than a decade ago, microfluidics has quickly become an important tool in several fields including new technologies as well as basic research. One reason for its fast development is based on the predictability of the flows at such scale and the exquisite control of interfaces in microchannels. Nowadays microfluidics has a place in many scientific fields. More often it is seen as a tool for the development of various topics related to chemistry, biology or physics. The list of possible applications and developed systems is very long and it is not the purpose of this chapter. In the following, we focus on the physics foundations on which this discipline relies. After a brief introduction on lab on chip technology, we introduce the basis of fluid mechanics with the governing equation for a fluid in motion. We also introduce diffusion transport and capillary effects which are dominant in microfluidic systems. Throughout the chapter we will illustrate the basic principles with practical examples.

Physical Review E, 2008

We study the rheology of sheared granular flows close to a jamming transition. We use the approac... more We study the rheology of sheared granular flows close to a jamming transition. We use the approach of partially fluidized theory ͑PFT͒ with a full set of equations extending the thin layer approximation derived previously for the description of the granular avalanches phenomenology. This theory provides a picture compatible with a local rheology at large shear rates ͓G. D. R. Midi, Eur. Phys. J. E 14, 341 ͑2004͔͒ and it works in the vicinity of the jamming transition, where a description in terms of a simple local rheology comes short. We investigate two situations displaying important deviations from local rheology. The first one is based on a set of numerical simulations of sheared soft two-dimensional circular grains. The next case describes previous experimental results obtained on avalanches of sandy material flowing down an incline. Both cases display, close to jamming, significant deviations from the now standard Pouliquen's flow rule ͓O. Pouliquen, Phys. Fluids 11, 542 ͑1999͒; 11, 1956 ͑1999͔͒. This discrepancy is the hallmark of a strongly nonlocal rheology and in both cases, we relate the empirical results and the outcomes of PFT. The numerical simulations show a characteristic constitutive structure for the fluid part of the stress involving the confining pressure and the material stiffness that appear in the form of an additional dimensionless parameter. This constitutive relation is then used to describe the case of sandy flows. We show a quantitative agreement as far as the effective flow rules are concerned. A fundamental feature is identified in PFT as the existence of a jammed layer developing in the vicinity of the flow arrest that corroborates the experimental findings. Finally, we study the case of solitary erosive granular avalanches and relate the outcome with the PFT analysis.

Lab on a Chip, 2013

We propose a microfluidics device whose main functional part consists of a microcapillary produce... more We propose a microfluidics device whose main functional part consists of a microcapillary produced by the self-rolling of a thin poly(dimethylsiloxane) film. Rolling is caused by inhomogeneous swelling of the film, pre-treated by oxygen plasma, in the vapour of chloroform. The capillaries are integrated with external electrical circuits by co-rolling electrodes and micro-resistors. The local control of temperature in the tubes by Joule heating is illustrated via the rate of an intra-tubular chemiluminescent reaction. The novel tubes with engineered inner structure can find numerous advanced applications such as functional elements of integrated microfluidics circuits.

We present a new route for the fabrication of highly specialized micro-capillaries, based on the ... more We present a new route for the fabrication of highly specialized micro-capillaries, based on the phenomenon of thin polymer films self-rolling. Before rolling, the surface can be patterned (chemically, topographically), permitting the fabrication of inexpensive fully functionalized capillaries. Spontaneous curvature is a well-known instability [1] which occurs in films with gradients of stress along the normal axis. Recently, this effect was used to fabricate tubes as a self-assembly process [2]. We focus on the application of those self-rolled microsystems to lab-on-chip technology. We propose methods to induce the spontaneous rolling of polymeric films, more precisely polydimethylsiloxane (PDMS). The advantage of such system is threefold: i-Those systems are inexpensive to design. ii-The inner surface of the capillary is accessible before rolling and can be properly functionalized and characterized. iii-The formation of the channel itself is not a lithographic process. The fabrica...

This review presents an overview of the different techniques developed over the last decade to re... more This review presents an overview of the different techniques developed over the last decade to regulate the temperature within microfluidic systems. A variety of different approaches has been adopted, from external heating sources to Joule heating, microwaves or the use of lasers to cite just a few examples. The scope of the technical solutions developed to date is impressive and encompasses for instance temperature ramp rates ranging from 0.1 to 2,000 °C/s leading to homogeneous temperatures from −3 °C to 120 °C, and constant gradients from 6 to 40 °C/mm with a fair degree of accuracy. We also examine some recent strategies developed for applications such as digital microfluidics, where integration of a heating source to generate a temperature gradient offers control of a key parameter, without necessarily requiring great accuracy. Conversely, Temperature Gradient Focusing requires high accuracy in order to control both the concentration and separation of charged species. In addition, the Polymerase Chain Reaction requires both accuracy (homogeneous temperature) and integration to carry out demanding heating cycles. The spectrum of applications requiring temperature regulation is growing rapidly with increasingly important implications for the physical, chemical and biotechnological sectors, depending on the relevant heating technique.

Journal of Colloid and Interface Science

arXiv: Soft Condensed Matter, 2014

Recent progress in colloidal science has led to elaborate self-assembled structures whose complex... more Recent progress in colloidal science has led to elaborate self-assembled structures whose complexity raises hopes for elaborating new materials. However, the throughputs are extremely low and consequently, the chance to produce materials of industrial interest, for instance, groundbreaking optical devices, harnessing complete three-dimensional band gaps, is markedly low. We discovered a novel hydrodynamic effect that may unlock this bottleneck. It is based on the dipolar flow interactions that build up when droplets are slowed down by the microchannel walls along which they are transported. Coupled with depletion forces, we succeeded to form, via a continuous flow process, at unprecedented speeds and under exquisite control, a rich ensemble of monodisperse planar and tridimensional clusters, such as chains, triangles, diamonds, tetahedrons, heterotrimers, possessing geometrical, chemical, and/or magnetic anisotropies enabling directional bonding. Continuous productions of millions o...

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Self-rolled polymer film: a promising route to microfluidic devices Rémy Brossard, Baptiste Sarrazin, Patrick Guenoun, Florent Malloggi

We report on the development of a PDMS microdevice integrating a magnetic chamber dedicated to ma... more We report on the development of a PDMS microdevice integrating a magnetic chamber dedicated to magnetic nanoparticles trapping / release. This magnetic chamber consists in ferromagnetic iron beads, packed by a physical restriction, that present the capability of concentrating magnetic field lines from external permanent magnet. It results an enhanced magnetic flux density and therefore high magnetic force within the magnetic chamber. The microdevice has been characterized with finite element numerical simulation and fluorescent microscope imaging. Setting the flow rate at 100 μl/h, nanoparticles enrichment about 4000-fold has been achieved with a trapping / release sequence of a few seconds.

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Ions at interfaces: accessing the first nanometers using X-ray standing waves Soumaya Ben-Jabrallah, Florent Malloggi, Luc Belloni, Luc Girard, Dmitri Novikov, Cristian Mocuta, Dominique Thiaudière, Jean Daillant,

We report on the development of a microdevice dedicated to allergy diagnosis which combines both ... more We report on the development of a microdevice dedicated to allergy diagnosis which combines both the advantages of homogeneous and heterogeneous immunoassays (IAs). As allergy diagnosis is based on IgE quantitation, we have used magnetic core shell nanoparticles (MCSNPs) as IgE capture nanoplateform. Integrating such immunosupport allows to perform the target antibody (IgE) capture in colloidal phase and thus to increase the IgE capture kinetics. Moreover, due to their magnetic properties and to the magnetic trap we have previously developed, the MCSNPs and therefore the target will be confined and preconcentrated prior the detection step. This microfluidic approach has been successfully developed for allergy diagnosis. The assay time was 20 min with a IgE limit of detection of 1 ng/mL.

In recent years, microfluidic-based sample preparation techniques have emerged as a powerful tool... more In recent years, microfluidic-based sample preparation techniques have emerged as a powerful tool for measurements at large scale X-ray facilities. Most often the microfluidic device was a form of hybrid system, i.e. an assembly of different materials, because a simple, versatile and inexpensive microfabrication method, on the one hand, and X-ray compatibility, on the other hand, cannot generally be achieved by the same material. The arrival of a new polymer family based on off-stoichiometric thiol-ene-epoxy (OSTE+) has recently redistributed the cards. In this context, we studied the relevance and the compatibility of OSTE+ for small-angle X-ray scattering (SAXS) studies. The material was characterized regarding its X-ray properties (transmission coefficient, attenuation coefficient, scattering pattern and polymer aging under X-ray light) and their comparison with those of the usual polymers used in microfluidics and/or for synchrotron radiation experiments. We show that OSTE+ has ...

Langmuir, 2008

We study the detachment of conductive aqueous drops in ambient oil from an electrode in the prese... more We study the detachment of conductive aqueous drops in ambient oil from an electrode in the presence of ac electric fields. Making use of the electrowetting effect, we determine the charge of the detached sessile drops. Drops are found to be discharged at high ac frequency in line with earlier predictions. At low frequencies, we find a wide but unexpected charge distribution displaying a frequency-dependent nonzero minimum charge. This observation is explained in terms of the stabilization of capillary bridges in electric fields, which prevents the hydrodynamic pinch-off for certain phases of the ac field.

Lab on a Chip

We present an innovative microfluidic-based system that automatizes the mutation accumulation cul... more We present an innovative microfluidic-based system that automatizes the mutation accumulation culture in budding yeast. We speed up by one order of magnitude the time necessary for genome-wide measurements of mutational profiles.

Lab on a chip, 2011

Magnetic core shell nanoparticles (MCSNPs) 30 nm diameter with a magnetic weight of 10% are usual... more Magnetic core shell nanoparticles (MCSNPs) 30 nm diameter with a magnetic weight of 10% are usually much too small to be trapped in microfluidic systems using classical external magnets. Here, a simple microchip for efficient MCSNPs trapping and release is presented. It comprises a bed of micrometric iron beads (6-8 μm diameter) packed in a microchannel against a physical restriction and presenting a low dead volume of 0.8 nL. These beads of high magnetic permeability are used to focus magnetic field lines from an external permanent magnet and generate local high magnetic gradients. The nanoparticles magnetic trap has been characterised both by numerical simulations and fluorescent MCSNPs imaging. Numerical simulations have been performed to map both the magnetic flux density and the magnetic force, and showed that MCSNPs are preferentially trapped at the iron bead magnetic poles where the magnetic force is increased by 3 orders of magnitude. The trapping efficiency was experimental...