Sebastien Jiguet | Ecole Polytechnique Federale de Lausanne (original) (raw)
Papers by Sebastien Jiguet
TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664), 2003
... have heen started, and in particular on the use of composite materials made of ceramic partic... more ... have heen started, and in particular on the use of composite materials made of ceramic particles embedded in a polymer matrix [II]. ... b) Micro-object made in composite PPL ... Alumina nano-particles were used as fillers in a photosensitive acrylate based resin having a low viscosity ...
Procedia Chemistry, 2009
This paper presents the study of a novel scintillation detector based on standard microfabricatio... more This paper presents the study of a novel scintillation detector based on standard microfabrication techniques. It consists of a fine pitch array of hollow waveguides filled with a liquid scintillator and optically coupled to photodetectors. The detector has been fabricated by patterning the SU-8 photoresist on silicon wafers. Experimental studies have been performed by exciting the liquid scintillator contained in the SU-8 waveguides with electrons. The scintillation light produced was read out by an external photodetector. The results obtained with this set-up demonstrate the concept of microfluidic scintillation detection and are very encouraging for future developments.
17th IEEE International Conference on Micro Electro Mechanical Systems. Maastricht MEMS 2004 Technical Digest, 2004
MRS Proceedings, 2002
Microstereolithography is a technology at the interface of the microengineering and rapid prototy... more Microstereolithography is a technology at the interface of the microengineering and rapid prototyping domains. It has evolved from the stereolithography technique, and is also based on a light-induced layer-stacking manufacturing. As the resolution of the microstereolithography technique is far better than the one of rapid prototyping technologies, this technique is of particular interest in the microengineering domain where its 3D capability allows the production of components no other microfabrication technique can create.
Surface and Coatings Technology, 2006
The increasing interests in micro-electro-mechanical systems (MEMS) has raised the requirement fo... more The increasing interests in micro-electro-mechanical systems (MEMS) has raised the requirement for photoresist materials with improved friction and wear properties for mechanically loaded 3D shaped microstructures. In this work, SU8 photoresist layers reinforced with different amounts of silica nanoparticles were produced and thermally treated. Dry sliding tests indicate that SU8 composite epoxies produced in the form of thin films exhibit similar or even better tribological properties than bulk epoxies. The SU8 nanocomposites exhibit reduced wear rates and frictional coefficient compared to the un-reinforced material. Further, nanoparticle content, heat treatment and nature of the sliding counter piece were found to affect wear and friction. The tribological behaviour was discussed in terms of mechanical properties and contact pressures.
Sensors and Actuators A: Physical, 2010
ABSTRACT A novel type of particle detector based on scintillation, with precise spatial resolutio... more ABSTRACT A novel type of particle detector based on scintillation, with precise spatial resolution and high radiation hardness, is being studied. It consists of a single microfluidic channel filled with a liquid scintillator and is designed to define an array of scintillating waveguides each independently coupled to a photodetector. Prototype detectors built using an SU-8 epoxy resin have been tested with electrons from a radioactive source. The experimental results show a light yield compatible with the theoretical expectations and confirm the validity of the approach.
physica status solidi (b), 2009
SU8carbon nanotube composites have been produced to enhance the mechanical, electrical, and ther... more SU8carbon nanotube composites have been produced to enhance the mechanical, electrical, and thermal properties of SU8 photoresists. Homogeneous composites materials have been obtained when multiwalled carbon nanotubes (MWCNTs) functionalized with ...
physica status solidi (b), 2010
ABSTRACT Multiwalled carbon nanotubes (MWCNTs)/SU8 composites have been produced to enhance the m... more ABSTRACT Multiwalled carbon nanotubes (MWCNTs)/SU8 composites have been produced to enhance the mechanical properties of SU8 photoresist. We have studied the influence of SU8 solvent on the structural homogeneity of composites through nanoindentation testing. It is found that acetone and propylene glycol methyl ether acetate (PGMEA) are very suitable solvents to prepare MWCNTs/SU8 composites with significant increase of the Young's modulus (EY). The highest increase of EY in respect to the parent material of 104% was obtained with acetone as solvent. It was noticed that the remaining solvent in the composite influences strongly EY, as well.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2010
A novel liquid scintillation detector with high spatial resolution is being developed with standa... more A novel liquid scintillation detector with high spatial resolution is being developed with standard microfabrication techniques. It consists of a dense array of scintillating waveguides obtained by filling microfluidic channels with an organic liquid scintillator and optically coupled to a pixellated photodetector. Such a microfluidic device can be designed and processed to meet the requirements of a wide range of applications like medical imaging, homeland security and high-energy physics. Highspatial resolution miniaturized detectors as well as large-area detectors can easily be fabricated. The fabrication process of a prototype detector and experimental results are presented in this paper.
Microfluidics and Nanofluidics, 2011
SU-8 photoresist is commonly used in the field of microfabrication as structural material or for ... more SU-8 photoresist is commonly used in the field of microfabrication as structural material or for molding of microfluidic devices. One major limitation, however, is the difficulty to process partially freestanding SU-8 structures or monolithic closed cavities and channels on-chip. We propose here a simple method for the fabrication of suspended structures, in particular of monolithic SU-8 microchannels. The method is based on the processing of a SU-8 doublelayer. Appropriate modification of the optical properties of the upper layer allows for selective crosslinking in the layer sandwich. This process is suitable for versatile layouts comprising open and hollow SU-8 structures on the same chip.
Microelectronic Engineering, 2006
The use of low-stress SU8 nanocomposites as a functional material for micro-parts and coating app... more The use of low-stress SU8 nanocomposites as a functional material for micro-parts and coating applications is described in this paper. It was found that the nanoparticles lower the internal stress and decrease the wear rate and frictional coefficient of the SU8 epoxy. The applicability of this technology is demonstrated on gear wheels configuration and coating multilayer capping technology on moving micro-parts.
Microelectronic Engineering, 2006
ABSTRACT A new nanocomposite photoresist based on SU-8 epoxy resin has been developed. It consist... more ABSTRACT A new nanocomposite photoresist based on SU-8 epoxy resin has been developed. It consists in a homogeneous dispersion of nano-silica particles in the negative tone photosensitive SU-8. The nanocomposite photoresist is more sensitive than the SU-8 photoresist and the photopatterned composite structures show low stress and less cracks than pure SU-8 structures. No significant resolution difference has been observed for both materials.
Lab on a Chip, 2004
The following paper describes a sacrificial layer method for the manufacturing of microfluidic de... more The following paper describes a sacrificial layer method for the manufacturing of microfluidic devices in polyimide and SU-8. The technique uses heat-depolymerizable polycarbonates embedded in polyimide or SU-8 for the generation of microchannels and sealed cavities. The volatile decomposition products originating from thermolysis of the sacrificial material escape out of the embedding material by diffusion through the cover layer. The fabrication process was studied experimentally and theoretically with a focus on the decomposition of the sacrificial materials and their diffusion through the polyimide or SU-8 cover layer. It is demonstrated that the sacrificial material removal process is independent of the actual channel geometry and advances linearly with time unlike conventional sacrificial layer techniques. The fabrication method provides a versatile and fast technique for the manufacturing of microfluidic devices for applications in the field of mTAS and Lab-on-a-Chip.
Journal of Micromechanics and Microengineering, 2004
Microstereolithography is a technique that allows the manufacture of small and complex three-dime... more Microstereolithography is a technique that allows the manufacture of small and complex three-dimensional (3D) components in plastic material. Many of the components produced by this technique are too small and too complex to be replicated by molding and, consequently, the produced components need to have adequate mechanical or chemical characteristics to be useful. Until now, the choice of materials available
Journal of Micromechanics and Microengineering, 2011
We report a process for the realization of polyimide films with custom-designed microporosity bas... more We report a process for the realization of polyimide films with custom-designed microporosity based on the heat-induced depolymerization of polyimide-embedded polypropylene carbonate microstructures. The foam-like microstructures are up to 40 µm ...
IEEE Transactions on Nuclear Science, 2000
A new type of scintillation detector is being developed with standard microfabrication techniques... more A new type of scintillation detector is being developed with standard microfabrication techniques. It consists of a dense arrayof scintillating waveguidesobtainedby couplingmicrofluidic channelsfilledwithaliquidscintillatortophotodetectors.Easyma- nipulation of liquid scintillators inside microfluidic devices allow their flushing, renewal, and exchange making the active medium intrinsically radiation hard. Prototype detectors have been fabri- cated by photostructuration of a radiation hard epoxy resin (SU-8) deposited on
Advanced Functional Materials, 2005
Advanced Engineering Materials, 2004
Composite materials offer a combination of properties and a diversity of applications, which cann... more Composite materials offer a combination of properties and a diversity of applications, which cannot be obtained with metals, ceramics or polymers alone. In particular, the insertion of a conductive phase (metallic or inorganic powders or conductive polymers) in an insulating polymer matrix, can result in an enhancement of its electrical conductivity. Various studies have been focused on such electrically conductive polymer composition (ECPCs), which do not have the disadvantages of the pure metal (high density, low chemical resistance, complex manufacturing process). The powder loaded polymer becomes a functional material with specific properties, and can be used for electrical or electromagnetic applications, etc. The case of ECPCs based on epoxy resins, are of particular interest to understand the properties of binary composites (morphology, electrical and thermal conductivity), which are obtained in most cases after a heat treatment to crosslink the ECPCs materials. Their main application is conductive adhesives used in the electronic field for connecting and bonding, but it can also be used for manufacturing sensors. [3±5] In this paper we report a new conductive photosensitive composite material, allowing the direct manufacture of electrically conductive micro-components. It is based on a blend containing silver particles embedded in SU-8, an epoxy photopolymer essentially used for the fabrication of high aspect ratio structures by UV-LIGA. SU-8 components are useful for MEMS, fluidic and packaging applications, [6,7] but also as masters for micro-injection-molding .
Nanoscale, 2014
Cell-derived membrane vesicles that are released in biofluids, like blood or saliva, are emerging... more Cell-derived membrane vesicles that are released in biofluids, like blood or saliva, are emerging as potential non-invasive biomarkers for diseases, such as cancer. Techniques capable of measuring the size and concentration of membrane vesicles directly in biofluids are urgently needed. Fluorescence single particle tracking microscopy has the potential of doing exactly that by labelling the membrane vesicles with a fluorescent label and analysing their Brownian motion in the biofluid. However, an unbound dye in the biofluid can cause high background intensity that strongly biases the fluorescence single particle tracking size and concentration measurements. While such background intensity can be avoided with light sheet illumination, current set-ups require specialty sample holders that are not compatible with high-throughput diagnostics. Here, a microfluidic chip with integrated light sheet illumination is reported, and accurate fluorescence single particle tracking size and concentration measurements of membrane vesicles in cell culture medium and in interstitial fluid collected from primary human breast tumours are demonstrated.
TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664), 2003
... have heen started, and in particular on the use of composite materials made of ceramic partic... more ... have heen started, and in particular on the use of composite materials made of ceramic particles embedded in a polymer matrix [II]. ... b) Micro-object made in composite PPL ... Alumina nano-particles were used as fillers in a photosensitive acrylate based resin having a low viscosity ...
Procedia Chemistry, 2009
This paper presents the study of a novel scintillation detector based on standard microfabricatio... more This paper presents the study of a novel scintillation detector based on standard microfabrication techniques. It consists of a fine pitch array of hollow waveguides filled with a liquid scintillator and optically coupled to photodetectors. The detector has been fabricated by patterning the SU-8 photoresist on silicon wafers. Experimental studies have been performed by exciting the liquid scintillator contained in the SU-8 waveguides with electrons. The scintillation light produced was read out by an external photodetector. The results obtained with this set-up demonstrate the concept of microfluidic scintillation detection and are very encouraging for future developments.
17th IEEE International Conference on Micro Electro Mechanical Systems. Maastricht MEMS 2004 Technical Digest, 2004
MRS Proceedings, 2002
Microstereolithography is a technology at the interface of the microengineering and rapid prototy... more Microstereolithography is a technology at the interface of the microengineering and rapid prototyping domains. It has evolved from the stereolithography technique, and is also based on a light-induced layer-stacking manufacturing. As the resolution of the microstereolithography technique is far better than the one of rapid prototyping technologies, this technique is of particular interest in the microengineering domain where its 3D capability allows the production of components no other microfabrication technique can create.
Surface and Coatings Technology, 2006
The increasing interests in micro-electro-mechanical systems (MEMS) has raised the requirement fo... more The increasing interests in micro-electro-mechanical systems (MEMS) has raised the requirement for photoresist materials with improved friction and wear properties for mechanically loaded 3D shaped microstructures. In this work, SU8 photoresist layers reinforced with different amounts of silica nanoparticles were produced and thermally treated. Dry sliding tests indicate that SU8 composite epoxies produced in the form of thin films exhibit similar or even better tribological properties than bulk epoxies. The SU8 nanocomposites exhibit reduced wear rates and frictional coefficient compared to the un-reinforced material. Further, nanoparticle content, heat treatment and nature of the sliding counter piece were found to affect wear and friction. The tribological behaviour was discussed in terms of mechanical properties and contact pressures.
Sensors and Actuators A: Physical, 2010
ABSTRACT A novel type of particle detector based on scintillation, with precise spatial resolutio... more ABSTRACT A novel type of particle detector based on scintillation, with precise spatial resolution and high radiation hardness, is being studied. It consists of a single microfluidic channel filled with a liquid scintillator and is designed to define an array of scintillating waveguides each independently coupled to a photodetector. Prototype detectors built using an SU-8 epoxy resin have been tested with electrons from a radioactive source. The experimental results show a light yield compatible with the theoretical expectations and confirm the validity of the approach.
physica status solidi (b), 2009
SU8carbon nanotube composites have been produced to enhance the mechanical, electrical, and ther... more SU8carbon nanotube composites have been produced to enhance the mechanical, electrical, and thermal properties of SU8 photoresists. Homogeneous composites materials have been obtained when multiwalled carbon nanotubes (MWCNTs) functionalized with ...
physica status solidi (b), 2010
ABSTRACT Multiwalled carbon nanotubes (MWCNTs)/SU8 composites have been produced to enhance the m... more ABSTRACT Multiwalled carbon nanotubes (MWCNTs)/SU8 composites have been produced to enhance the mechanical properties of SU8 photoresist. We have studied the influence of SU8 solvent on the structural homogeneity of composites through nanoindentation testing. It is found that acetone and propylene glycol methyl ether acetate (PGMEA) are very suitable solvents to prepare MWCNTs/SU8 composites with significant increase of the Young's modulus (EY). The highest increase of EY in respect to the parent material of 104% was obtained with acetone as solvent. It was noticed that the remaining solvent in the composite influences strongly EY, as well.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2010
A novel liquid scintillation detector with high spatial resolution is being developed with standa... more A novel liquid scintillation detector with high spatial resolution is being developed with standard microfabrication techniques. It consists of a dense array of scintillating waveguides obtained by filling microfluidic channels with an organic liquid scintillator and optically coupled to a pixellated photodetector. Such a microfluidic device can be designed and processed to meet the requirements of a wide range of applications like medical imaging, homeland security and high-energy physics. Highspatial resolution miniaturized detectors as well as large-area detectors can easily be fabricated. The fabrication process of a prototype detector and experimental results are presented in this paper.
Microfluidics and Nanofluidics, 2011
SU-8 photoresist is commonly used in the field of microfabrication as structural material or for ... more SU-8 photoresist is commonly used in the field of microfabrication as structural material or for molding of microfluidic devices. One major limitation, however, is the difficulty to process partially freestanding SU-8 structures or monolithic closed cavities and channels on-chip. We propose here a simple method for the fabrication of suspended structures, in particular of monolithic SU-8 microchannels. The method is based on the processing of a SU-8 doublelayer. Appropriate modification of the optical properties of the upper layer allows for selective crosslinking in the layer sandwich. This process is suitable for versatile layouts comprising open and hollow SU-8 structures on the same chip.
Microelectronic Engineering, 2006
The use of low-stress SU8 nanocomposites as a functional material for micro-parts and coating app... more The use of low-stress SU8 nanocomposites as a functional material for micro-parts and coating applications is described in this paper. It was found that the nanoparticles lower the internal stress and decrease the wear rate and frictional coefficient of the SU8 epoxy. The applicability of this technology is demonstrated on gear wheels configuration and coating multilayer capping technology on moving micro-parts.
Microelectronic Engineering, 2006
ABSTRACT A new nanocomposite photoresist based on SU-8 epoxy resin has been developed. It consist... more ABSTRACT A new nanocomposite photoresist based on SU-8 epoxy resin has been developed. It consists in a homogeneous dispersion of nano-silica particles in the negative tone photosensitive SU-8. The nanocomposite photoresist is more sensitive than the SU-8 photoresist and the photopatterned composite structures show low stress and less cracks than pure SU-8 structures. No significant resolution difference has been observed for both materials.
Lab on a Chip, 2004
The following paper describes a sacrificial layer method for the manufacturing of microfluidic de... more The following paper describes a sacrificial layer method for the manufacturing of microfluidic devices in polyimide and SU-8. The technique uses heat-depolymerizable polycarbonates embedded in polyimide or SU-8 for the generation of microchannels and sealed cavities. The volatile decomposition products originating from thermolysis of the sacrificial material escape out of the embedding material by diffusion through the cover layer. The fabrication process was studied experimentally and theoretically with a focus on the decomposition of the sacrificial materials and their diffusion through the polyimide or SU-8 cover layer. It is demonstrated that the sacrificial material removal process is independent of the actual channel geometry and advances linearly with time unlike conventional sacrificial layer techniques. The fabrication method provides a versatile and fast technique for the manufacturing of microfluidic devices for applications in the field of mTAS and Lab-on-a-Chip.
Journal of Micromechanics and Microengineering, 2004
Microstereolithography is a technique that allows the manufacture of small and complex three-dime... more Microstereolithography is a technique that allows the manufacture of small and complex three-dimensional (3D) components in plastic material. Many of the components produced by this technique are too small and too complex to be replicated by molding and, consequently, the produced components need to have adequate mechanical or chemical characteristics to be useful. Until now, the choice of materials available
Journal of Micromechanics and Microengineering, 2011
We report a process for the realization of polyimide films with custom-designed microporosity bas... more We report a process for the realization of polyimide films with custom-designed microporosity based on the heat-induced depolymerization of polyimide-embedded polypropylene carbonate microstructures. The foam-like microstructures are up to 40 µm ...
IEEE Transactions on Nuclear Science, 2000
A new type of scintillation detector is being developed with standard microfabrication techniques... more A new type of scintillation detector is being developed with standard microfabrication techniques. It consists of a dense arrayof scintillating waveguidesobtainedby couplingmicrofluidic channelsfilledwithaliquidscintillatortophotodetectors.Easyma- nipulation of liquid scintillators inside microfluidic devices allow their flushing, renewal, and exchange making the active medium intrinsically radiation hard. Prototype detectors have been fabri- cated by photostructuration of a radiation hard epoxy resin (SU-8) deposited on
Advanced Functional Materials, 2005
Advanced Engineering Materials, 2004
Composite materials offer a combination of properties and a diversity of applications, which cann... more Composite materials offer a combination of properties and a diversity of applications, which cannot be obtained with metals, ceramics or polymers alone. In particular, the insertion of a conductive phase (metallic or inorganic powders or conductive polymers) in an insulating polymer matrix, can result in an enhancement of its electrical conductivity. Various studies have been focused on such electrically conductive polymer composition (ECPCs), which do not have the disadvantages of the pure metal (high density, low chemical resistance, complex manufacturing process). The powder loaded polymer becomes a functional material with specific properties, and can be used for electrical or electromagnetic applications, etc. The case of ECPCs based on epoxy resins, are of particular interest to understand the properties of binary composites (morphology, electrical and thermal conductivity), which are obtained in most cases after a heat treatment to crosslink the ECPCs materials. Their main application is conductive adhesives used in the electronic field for connecting and bonding, but it can also be used for manufacturing sensors. [3±5] In this paper we report a new conductive photosensitive composite material, allowing the direct manufacture of electrically conductive micro-components. It is based on a blend containing silver particles embedded in SU-8, an epoxy photopolymer essentially used for the fabrication of high aspect ratio structures by UV-LIGA. SU-8 components are useful for MEMS, fluidic and packaging applications, [6,7] but also as masters for micro-injection-molding .
Nanoscale, 2014
Cell-derived membrane vesicles that are released in biofluids, like blood or saliva, are emerging... more Cell-derived membrane vesicles that are released in biofluids, like blood or saliva, are emerging as potential non-invasive biomarkers for diseases, such as cancer. Techniques capable of measuring the size and concentration of membrane vesicles directly in biofluids are urgently needed. Fluorescence single particle tracking microscopy has the potential of doing exactly that by labelling the membrane vesicles with a fluorescent label and analysing their Brownian motion in the biofluid. However, an unbound dye in the biofluid can cause high background intensity that strongly biases the fluorescence single particle tracking size and concentration measurements. While such background intensity can be avoided with light sheet illumination, current set-ups require specialty sample holders that are not compatible with high-throughput diagnostics. Here, a microfluidic chip with integrated light sheet illumination is reported, and accurate fluorescence single particle tracking size and concentration measurements of membrane vesicles in cell culture medium and in interstitial fluid collected from primary human breast tumours are demonstrated.