Coordinator : J. F. Dayen
Scientific leader IS2M : L. Simon
MIXES is a collaborative research project that explores the fundamental structural and electronic properties of novel 2D-0D nanomaterial, made of 2D materials in interaction with self-ordered nanoclusters grown using dry methods compatible with microelectronics industry processes. First results show that these nanomaterials, once implemented into tunnel junctions, demonstrate robust Coulomb blockade oscillations and magneto-Coulomb properties, preserved on device being 6 orders of magnitude larger than usual single-electron devices. These results have raised questions regarding the underlying fundamental physics that are addressed by this project. In particular, we will address the following fundamental questions : i) What is the chemical/structural/electronic nature of the 2D/0D interface ? How are the local/extended structural and electronic properties of 2D/0D nanomaterials influenced by the nature of the 2D/0D interface, when it varies from van der Waals type to covalently bound ? (ii) What is the key mechanism behind many dissimilar nanoclusters apparently behaving as single or identical entities in the 2D-0D nanomaterial ? How can it be mastered for simple and large-scale processing of a single electron device ? iii) Can it be extended to other 2D materials such as dichalcogenic transition metals ? iv) How can these properties be used to create new single electron multifunctional devices ? We follow an interdisciplinary approach covering ab-initio modelling, surface science, structural analysis, nanofabrication and transport measurements. We keep as final goal to use these new knowledges to build novel architecture of multifunctional single-electron electronics and spintronics devices, operating up to room temperature.
Optical Engineering of Chemo-responsive Multiplex Materials
Coordinator :Jean-Luc Fillaut
Scientific leader IS2M : Jean-Pierre Malval
This project is devoted to the engineering of sub-micrometer structured polymer materials dedicated to luminescent multi-purpose chemical sensing.
Our approach is based on the two-photon assisted fabrication and post-functionalization of 3D polymer materials for implementing molecular luminescent reporters and probes.
Dynamic Sensor for Nano Biomarker
Coordinator : Marc Frouin
Scientific leader IS2M : Olivier Soppera
Heart failure (HF) is a major public health problem affecting 23 million people worldwide. Most of patients must be frequently monitored.
DYNABIO final target is a medical portable monitoring device able to ensure a continuous monitoring of the main HF biomarkers by using non-invasive biocompatible nanosensors. The device would allow the continuous monitoring of unstable patients without request to have frequent blood samples sent to analysis robots. It will combine the practical use of a telemedicine monitoring tool capable to copilot the patient health dynamically with the accurate measurement of main HF biomarkers from the sensors sampling in subcutaneous fluids or micro vascularized blood samples.
Reactivable photo-polymers for 3D additive fabrication
Coordinator : Jean-Louis Clément
Scientific leader IS2M : Arnaud Spangenberg
3D Printing has significantly lowered the barrier-of-entry in terms of cost, time and accessibility to micro-fabricated intricate shapes and sophisticated devices, in various fundamental research domains. 3D printers can manufacture objects with sizes ranging from few microns with two-photon stereolithography (TPS) to centimeter. In the field of microfluidics, the more “user-friendly” implementation and the easiness of 3D printing of complex structures digitally designed (3D CAD) compete the robust but heavy implementation of soft lithography. 3D printing allows direct and rapid fabrication of microfluidic chips. Among all 3D printing technologies, 3D printings based on stereolithography have attracted particular attention since sub-100 µm internal channel diameter has recently been demonstrated.
In this context, polymers are strategic materials. However, the main limitation relies on the fact that the properties of the chosen monomer impose the surface chemistry of the envisioned object. At technological level, substantial efforts have been devoted to improving writing devices (writing resolution and speed). However, little attention has been given to increasing the chemical diversity or surface functionalization of the written scaffolds. Today, it is not yet possible to modify the surface chemistry in a simple way from 3D printers other than robust but heavy and/or cumbersome post physical or chemical treatments. So mechanically compliant and chemically functionalized surfaces (polarity, texturing, biocompatibility, etc…) are still untenable. Moreover, it is a hard puzzle to solve when surface modifications are to be done at located place (patterning).
3D-CustomSurf project aims at developing new photo-initiator with advanced properties and new methodologies in additive manufacturing techniques 3DP-UV (mm to cm scale) and TPS (µm scale). Our strategy is grounded on the use of photo–Reversible-Deactivation Radical Polymerization (photo-RDRP) techniques adapted to the specific conditions of 3D manufacturing by photo-polymerization applied to microfluidics field where this will be an asset when specific patterning is needed. Indeed, surface modification of internal channels of a microfluidic device is still limited by multi-steps process.
Our strategy is grounded on i) the design and synthesis of unique photo-sensitive alkoxyamines containing specific chromophores for both 3DP-UV and TPS and the initiating moiety ii) a careful examination of their photo-physical and chemical properties iii) a thorough investigations of their efficiencies for first and re-polymerization (living polymerization) under laser writing (3DP-UV, TPS) iv) methodological investigations for first polymerization (3DP-UV) followed by inner surface functionalization (chemical and patterning) by TPS on simple prototypes (tubes) v) the fabrication of a microfluidic device with customized inner surface channels for double emulsion preparation.
Coupling laser writing with RDRP methodologies is a novel approach which has been poorly investigated notably in the field of TPS where no work has been reported with a such combination. Novelty and especially lack of thorough investigations about chemical and physical phenomena involved during the 3D fabrication process explain the absence of such approach in 3D laser printing area. Our strategy is expected to be a breakthrough in this field since .NMP2 coupled with 3D PrintingDLW allow to consider the object on the one hand and its surface modification (chemistry and structuration) on the other hand in a protocol of great simplicity. Our strategy is expected to be a breakthrough in this field.
Conception of bioresorbable self-rolled patchs for the local treatment of inflammation induced in the colon after irradiation
Coordinator : Noëlle Mathieu
Scientific leader IS2M : Karine Anselme
Pelvic cancers are among the most frequently diagnosed cancers worldwide. Radiotherapy (RT) plays a growing place in the management of malignant pelvic diseases. Even though great advances have been made in RT delivery techniques, radiation exposure of significant volumes of normal bowel persists, impacting on the patient’s quality of life post-treatment. Cancer incidence increases and mortality have been reduced during the past several decades, and the number of cancer survivors has almost tripled during the same period. With an increasing cohort of cancer survivors, efforts to manage the adverse effects of RT have to be intensified. Current therapies are merely palliative. Several drugs have been investigated to prevent the pelvic radiation disease (PRD), amifostine, derivative of 5-aminosalicylic acid (5-ASA), analog of prostaglandin, sucralfate and glucocorticoids but no curative treatment exists. Moreover, these pharmacologic molecules could induce adverse effects especially when they are delivered systemically with a prolonged use. We also demonstrated that cell therapy using mesenchymal stromal cells (MSC) gave encouraging results in animal models (rats and pigs), and could be a new perspective to induce regeneration of the colon.
Today, no medical device exists for the treatment of the colon despite the number of various colonic pathologies as inflammatory diseases. Few studies demonstrated poor results with hydrogel delivered by enema. The objective of OPENN is to develop an innovative medical device dedicated to the colon that could be easily implanted by surgeons using colonoscopy. This new medical device will be designed with self-rolling bilayer polymer films loaded with anti-inflammatory drugs or MSC. In situ, the self-rolled bilayer tube will unfold, selectively attach to the damaged area and release anti-inflammatory drugs or bioactive molecules produced by MSCs by directed diffusion toward the inflamed mucosa. The therapeutic benefit of this new patch will be tested in vivo in rat model developing colonic damages similar to those induced in patients suffering from severe side effects after radiotherapy.
OPENN project will be organized in Workpackages to develop self-rolled tubes with polymers (WP2), load the self-rolled tubes with anti-inflammatory molecules and analyse their release (WP3), develop the cellularized self-rolled tubes and control the cell viability (WP4), and test in rats model relevant to the human pathology induced after RT treatment, the therapeutic benefit of the devices on the structure and the function of the colon (WP5).
The OPENN project will have an impact in development and transfer of knowledge in the field of biomaterials and innovative implantable medical devices to reinforce the French position in this field. The potential of this project for commercialization is significant since systemic anti-inflammatory treatments used for chronic diseases induce numerous adverse effects. Moreover, the use of self-rolled patch loaded with MSCs is very innovative and will provide a new concept in regenerative medicine. The consortium of the OPENN project rallied skills of physicists, chemists and biologists towards a translational research problem dedicated to public health issue.
Mechanical Energy Storage and absorption in microporous materials by high-pressure intrusion of electrolyte solutions
Coordinator : Andrey Ryzhikov
Scientific leader IS2M : Andrey Ryzhikov
The project is devoted to development of new highly efficient heterogeneous lyophobic systems for mechanical energy storage and absorption based on high pressure intrusion-extrusion of electrolyte solutions in hydrophobic microporous materials such as pure-silica zeolites (zeosils) and Metal-Organic Frameworks. The understanding of intrusion mechanism at the atomistic and thermodynamic level is the main objective. The project includes the experiments on highly concentrated electrolyte aqueous solutions intrusion-extrusion in the porous solids with varying of cation and anion nature, the study of intrusion process by in situ calorimetry and molecular simulation of the process by Molecular Dynamics and Monte-Carlo methods.
Programmed drug release by rolled-up biopolymer capsules
Coordinator : Valeriy Luchnikov
Scientific leader IS2M : Valeriy Luchnikov
The pharmacokinetics of many medicaments : their resorbtion, distribution, methabolism and elimination depends on the hour of administration. As the consequence, these medicaments are more effective and/or better tolerated if taken at appropriate time. Non-uniform distribution of a medicament in a micro/nanoporous matrix media (tablets or capsules) constitutes an advanced approach to programming of diffusion-controlled drug release. However, creation of such media with complex distribution of the drugs is a challenging issue. We propose a simple and cheap method to create biopolymer cylindrical capsules with complex radial distributions of the drugs, and aim to explore the potential of the method for chronotherapies. The approach consists in rolling up thin biopolymer films functionalized by one drug or several drugs. The drugs pattern will be created on the biopolymer film stripes by inkjet printing. The films will be then rolled up due to internal gradient stress. The kinetics of the drugs release will be studied in physiological media proposed in the 8th European Pharmacopeia, and compared to numerical simulation models.
Germenene on band gap materials
Coordinator : Carmelo Pirri
Scientifique leader IS2M : Carmelo Pirri
01/10/2017 – 31/03/2021
The project aims at growing germanene, the germanium equivalent of graphene, and study the physics of Dirac fermions in this two-dimensional (2D) material. Indeed, germanene departs from conventional 2D electrons systems and graphene by a buckled atomic structure and a significant spin orbit coupling. It should thus form a rich playground for fundamental studies in low-dimensional physics. Based on the expertise recently gained with the growth of germanene on Al(111) by partners of this project, we want to explore the growth of van der Waals heterostructures, consisting of germanene and 2D layered materials, that allow to minimize the interaction between germanene and these supporting materials. For that purpose, our consortium will rely on state of the art in depth characterization tools at the nanoscale : synchrotron radiation, scanning probe microscopy at low temperature with multiple tips and time-resolved spectroscopy capability. Our analysis based on versatile multi-physical characterization will be compared with calculations performed in the framework of the density functional theory, highlighting the impact of the atomic arrangement on the band structure of germanene and how the nature of the substrate might perturb the structural and electronic properties of this remarkable sheet of Ge atoms. Relevant to this project will be the measurement of the Dirac cone hallmark, the band gap, the carrier mobility and the charge transfer from the underlying layer. Also, we will strive to demonstrate the existence of the quantum spin Hall effect, that is expected due to the substantial spin-orbit coupling in germanene. Of particular interest is the study of defects and lattice deformations, that opens the door to topological transitions, like the Kekulé distortion, causing the attachment of mass to Dirac Fermions. Because of the anticipated poor resistance of germanene to ambient conditions, what would severely limit a deeper characterization and prevent its use in spin/opto-electronic applications, efforts will also be devoted to encapsulate germanene. We want to achieve the growth of germanene on Al(111) ultra-thin films on silicon, followed by the removal of the Si parent substrate and the oxidation of the Al layer, and, to protect the top face of germanene with 2D layered materials transferred in ultra-high vacuum. These schemes will take place along with innovations in instrumentations, in particular Raman spectroscopy in ultra-high vacuum that is the tool of choice for fingerprinting 2D materials. French companies that are involved in the Equipex and Labex investment awards of two of the partner will benefit from transfers of know-how in advanced instrumentations. Progress in the field of the synthesis of germanene, in the understanding of the physics of this material and in the design of dedicated tools will be the key to turn germanene into practical technologies at the end of the project.
3D Photo-structuration of functional magnetic materials
Coordinator : Dominique Berling
Scientific leader IS2M : Dominique Berling
01/01/2017 – 31/01/2021
PHOTOMAGNET proposal proposes to develop new sol-gel matrices incorporating Magnetic Nanoparticles (NPM) homogeneously dispersed and which are photostructurable in 3D structures of sub-micron resolutions by two photon stereolithography (TPS). Last of all, demonstration of the applicative potentialities of these μ-structured functional nanocomposite materials will be achieved through two proofs of concept corresponding to a multifunctional material : photonic crystals and magnetothermal-μ structures.
The realization of 3D CMP seeks a Faraday rotation of exaltation than 1.5 microns by the own slow wave mechanism photonic crystals, while ensuring a good transmittance of micro-structured material. It is the interest of a realization by TPS which guarantees excellent uniformity of the microstructure compared to the self-organizing methods more typically employed to make CMP. Such a demonstration will completely lift the current lock Integration or micro-structuring conventional magneto-optical materials, lock that drastically limits the use of these materials in applications where they are nevertheless highly expected. For the magneto-thermal μ-structures, it is to build a network 2 D micro-pillars which are thermally activatable by application of an external magnetic field, this activation based on the own magnetic hyperthermia of NPM. Adapted for interaction with biological cells, these micro-nanostructured functional surfaces pave the way for the study of cellular events associated with hyperthermia. To characterize the best hyperthermia capacity NPM partners provide a magneto-optical measurement sensitive to internal temperature of these NPM during their thermal activation. Innovative compared with currently available tools, and coupled with the diversity of NPM available in the project, this measurement technique will, in no doubt, valuable information for the community on the mechanisms involved in magnetic hyperthermia.
This project is multidisciplinary and enforce the complementary skills of the three research groups involved in different scientific developments areas :
- i) Synthesis of functionalized NPM compatible with the selected matrix and exhibiting controlled magnetic properties will be a key initial step in this project.
- ii) The second ambitious challenge lies in the development of host matrices for NPM that will be photostructurable by two photon stereolithography. Several types of matrices are considered, hybrid sol-gel matrices (silane / acrylate) and matrices based on oxo-metallic clusters (Zr and Ti) whose structuration by TPS was recently validated.
iii) The interest will be demonstrated through two applications : resonant magneto-optical 3D structures and 3D microstructures presenting magneto thermic properties. In both cases, the TPS technique associated with these two photostructurable magnetic materials is the only technique to fabricate functional 3D complex microstructures. Since TPS is a rapid prototyping technology, it enables to modify at will the design of structures in order to achieve their looked-for properties.
Photovoltaic spatial light modulators for selfactivated dynamic glazing
Coordinator : Dimitri Ivanov
Scientific leader IS2M : Dimitri Ivanov
01/01/2020 – 31/12/2023
Dynamic glazing systems such as electrochromic, photochromic, or thermochromic glass, can improve considerably the energy efficiency of buildings. Their widespread utilization is however still limited by high costs, long payback periods, slow device response times, and lack of operational control. This project focuses on a new type of dynamic glazing system called photovoltaic spatial light modulator (PSLM). A PSLM is based on an optically addressed liquid crystal light modulator using an organic bulk heterojunction as photosensitive layer. PSLMs offer many advantages over existing technologies, but further, intensive research is required to push this concept from its current, successful demonstration of principle status to high technology readiness level. The major goal of this project is to achieve a better understanding of the device operation and to explore methods that are able to boost the PSLM performances and broaden its field of application.
Laser-assisted fabrication of silicone-based patches for transdermal drug release
Coordinator : V. Luchnikov
Scientific leader IS2M : V. Luchnikov (IS2M), T. Vandamme (partnership UNISTRA)
01/01/2020 – 31/12/2023
Silicone-based transdermal drug delivery patches are currently used in a wide range of pharmaceutical applications from hormone therapy to central nervous system related pathologies. However, their production has relatively high technology barrier, impacting their price and limiting their utilization. We aim to resolve this problem by developing a novel simple and cost-effective approach to the patches fabrication, based on infrared laser irradiation of polydimethylsiloxane layers. In previous works (Qi et al 2018, Tomba et al 2019) it was shown that intense irradiation can generate a few microns thick strongly oxidized layer on the surface of the PDMS films, without the films ablation. Preliminary experiments have shown that these films might serve as the barrier for the diffusion of small molecules in the elastomer matrix. This opens the way to create patches as the sequence of PDMS layer separated by the laser-oxidized interfaces of different permittivity for the drugs.
The structure of the oxidized layer will be investigated by SEM, AFM, IR and Raman spectroscopy. The transport properties of the membranes can be varied in continuous manner from semi-permeable to impermeable, via the application of different intensity and duration of the radiation. The permittivity of the interfaces will be quantified by the diffusion rate through the interface into liquid receiving media (phosphate buffer) with the use of the Franz cell. The less traditional approaches, such as diffusion in humidity-controlled synthetic skin system (Cai et al 2012) , and confocal microscopy measurement of the diffusion profiles of the model drugs (e.g. Rhodamine B) in PDMS receiving layer will be also applied for the characterization of the interface barrier properties.
Prototypes of the patches of different architectures will be tested. In the monolayer patches, the single PDMS layer, topped by an impermeable strongly oxidized film, will serve silultaneously the adhesive layer, the drug reservoir, and the mechanical support. In more complicated architectures, these functions will be assigned to different consequtive layers. The adhesive layer and the drug reservoir layer will be separated by semi-permeable interface, and the drug reservoir layer will be topped by the impermeable interface. The pressure-sensitive adhesion will be provided by low degree of crosslinking of the corresponding layer.
At the advanced stage of the project, we will work with real drugs models. Similar drugs than the ones used in the marketed transdermal drug delivery devices will be used. Two different model drugs such as scopolamine and oestradiol will be used. The determination of the release profiles will be explored with the use of the Franz cells, and the syntetic skin system (Cai et al. 2012). A dissolution bath apparatus 2 with mini vessels will be also used to perform the release test for patches. The patches will be fixed in the baskets and placed at the bottom of the vessel in pH 6.8 phosphate buffer. The concentration of the model drugs in the solution will be measured using isocratic reversed phase liquid HPLC. The fraction of drug release will be calculated from the total amount of drug in the patch. To analyze the active ingredients and to see if they are degraded by the irradiation, we shall make an assay by a double mass liquid chromatography (HPLC MS/MS). This will measure the active ingredient and any impurities (degradation products).
In vivo tests will be performed on nude rats (without hair). These tests will be carried out in the animal clinics of the University of Strasbourg and in particular at the laboratory animal house of the Faculty of Pharmacy. The in vivo tests will be performed after writing a referral that has been validated by the regulatory authorities.
Fabrication of functional thin films by combining deep UV nanolithography and solution colloidal nanocrystals processes.
Coordinator : Fabien Grasset
Scientific leader IS2M : D. BERLING
01/10/2018 – 06/01/2023
DUVNANO is a multidisciplinary project that intends to respond to the demand of new simple processes toward functional thin film by proposing a novel approach that combines colloidal nanocrystals solution and Deep-UV (DUV : 266 & 193 nm) photolithography processes. DUVNANO is a PRC project gathering 2 partners highly specialized on colloidal chemistry and DUV photolithography processes respectively : Laboratory for Innovative Key Materials and Structure-LINK (CNRS UMI 3629) and Institut de Science des Matériaux de Mulhouse-IS2M (CNRS UMR7361). In agreement with Axis 2 of Challenge 3, DUVNANO will focus on a wide range of materials in order to develop a new process rather than aiming for a particular application. The control of this new process will be validated through the realization of simple components such as field effect transistors (FET) or optical networks that can find applications in domain such as “smart windows” for instance.
The originality of DUVNANO lies in the use of colloidal nanocrystals solutions as negative tone photoresists for direct writing of functional microstructures by DUV photolithography, without any further process step. DUV irradiation has indeed the unique property to allow the crosslinking of nanocrystals (NCs) or nanoparticles (NPs) without any additional thermal treatment. With this process, inorganic micro-nanostructured thin films will be obtained in a single step, at room temperature, by a simple process compatible with flexible substrates. The research in coating material and process suitable for solution route is of great interest for industrial point of view. Indeed, thin films are playing a very important and indispensable role in daily life with a material market value estimated to be around $10 billion by 2018.
The project is organized in 4 main tasks : Task 0 will address the project management and will be led by LINK who will cover all administrative and technical management. Task 1 (led by LINK) will be focused on the synthesis and characterization of colloidal solution and thin films based on monodispersed and size-controlled NCs of typical oxides (ZnO, Fe2O3, SiO2…) or metals clusters ( Mo, Ta, Nb, Cu). The synthesis of colloidal solution could be done in aqueous or organic (ethanol, propanol, cyclohexane…). Chemical solution processes (dip and spin-coating, electrophoretic deposition) will be used to address the formation of thin films with good optical quality. Task 2 (led by IS2M) will deal with the DUV photopatterning. Patterning will be achieved by mask lithography, laser direct writing and interference lithography to cover a wide variety of structures and resolutions. The photopatterning will be adapted to the different categories of materials (semi-conductive oxides, dielectric oxides or metal clusters). Basic devices will be produced as described above. Task 3 (co-led by LINK&IS2M) will deal with the physical characterizations (optical, electrical or magneto-optical and magnetic properties).
In comparison to previous works (Wang et al, Science 2017), DUVNANO propose to develop a simpler and quicker process for preparing thin films without photoresists. Very recently, IS2M demonstrated the possibility of crosslinking NP synthetized by LINK. This gives the proof of concept of our goal in this project that is to obtain, directly after DUV irradiation, patterned fully inorganic and nanocrystalized materials. The methodology has been thought in order to minimize the risks using the complementary skills and know-how of each partner.
Aminocoatings for improving implants’ tissue integration: understanding underlying biological mechanisms
Coordinator : Dr Karine ANSELME (France) and Pr Barbara NEBE (Rostock University Medical Center, Germany)
Scientific leader IS2M : Dr Karine ANSELME
01/01/2021 – 31/12/2023
Aminocoatings for improving implants’ tissue integration : understanding underlying biological mechanisms
Aging of people in developed countries will further increase bone deficiencies due to pathologies such as osteoporosis. Therefore, the need of bioactive implants with the capacity to integrate inside osteoporotic bone will raise significantly. Surface chemistry and surface topography modifications have been shown to improve bone implants tissue integration. In a recent common work using model microfabricated surfaces, we demonstrated impressively the predominance of chemistry versus topography in influencing human bone cell response. Amine functionalization of geometrically grooved titanium-coated silicon substrates with plasma polymerized allylamine was able to abrogate the cell contact guidance along the microgrooves.
This was the first demonstration of the possibility to overcome a strong topographical signal by changing the surface chemistry.
Several hypotheses have been proposed to explain this effect : (a) the high electrostatic interactions that must occur between a negatively-charged cell membrane and the positively-charged amino residues ; (b) the increased adsorption of cell-adhesive proteins from the serum with more efficient conformation for interaction with integrin receptors ; (c) the capacity of polyamines residues released in culture medium to promote cell protrusion formation.
However, this original result obtained by our two groups with allylamine plasma polymer coatings needs now to be analysed more deeply to determine the role of physico-chemical surface properties and the biological mechanisms involved.
With the objective of determining the role of surface and/or volume density of amino groups in this cell response, we propose to develop controlled amino-rich nano-layers using three different techniques allowing increasing levels of control of chemical composition : (a) plasma polymerization, (b) covalent grafting of polymer-based amino-rich nano-coatings with varying content in amino groups, and (c) self-assembled monolayers with amino terminal groups.
On these perfectly characterized amino-rich organic surfaces, we will explore in depth what proteins adsorb from the serum, in which quantity and how they are conformed.
To verify the abrogation potential of these different surfaces in relationship with the density and organization of amino groups, the morphology of human bone cells will be evaluated in living and fixed cells on coated grooved substrates. The organization and dynamics of cytoskeleton and focal adhesions will be quantified to implement an in silico cell model and determine the adhesion force and mechanical properties of cells depending of the amino-rich nano-layers. Further, to go deeper into the analysis of the cellular mechanisms involved in cell response, both the signalling and the gene expression of the cells will be analysed.
Finally, the understanding of the mechanism of action of these amino-rich nano-layers shall bring basic knowledge essential for improving bioactive implants for deficient aged bone.
Coordinator : Véronique Bardinal
Scientific leader IS2M : Olivier Soppera
01/3/2021 – 31/8/2024
3D-BEAM-FLEX aims at developing a new method for coupling single-mode VCSEL arrays to single-mode optical fibers in order to improve VCSEL integration in high speed optical interconnects (datacom/telecom) and in miniaturized sensors. This method is based on the self-writing of a self-aligned and flexible waveguide via two photopolymerization steps, in the NIR and in the UV. Thanks to the overcoming of fundamental barriers (understanding of photochemical mechanisms, development of formulations sensitive at 0.8, 1.31 and 1.55μm, gradient index analysis, waveguide design) and of applied ones (demonstration of an efficient single-mode optical link, 90° beam redirection, multichannel fabrication) and to the association with 3D additive manufacturing techniques, we will demonstrate that this approach, simple and applicable at a post-processing stage, leads to an optimal coupling while relaxing the stringent tolerances on devices alignment.
NOPEROX : Peroxide-Free (Photo)Initiating Systems
Coordinator : Jacques LALEVÉE
Scientific leader IS2M : Jacques LALEVÉE
01/01/2020 – 31/12/2023
Coordinator : Jacques LALEVÉE
Scientific leader IS2M : Jacques LALEVÉE
06/01/2020 – 05/01/2024
IR-EMULSION : IR-Photopolymerization in Dispersed Media
The overall aim of the project is to use for the first time Near Infra-Red light (both in the NIR ~ 780 nm and in the SWIR ~ 1300 nm) to initiate photopolymerizations in dispersed media (emulsion and dispersion). We will build on our previous experience in blue-light emulsion photopolymerization on the one hand, and IR-triggered bulk polymerization and nanopatterning on the other hand.
The combination of the advantages of both dispersed media polymerizations (such as low exposition to volatile organic compounds, low viscosity of the reaction media and of the resulting latexes, high polymerization rates and solids contents[i]) and photo-polymerizations (spatial and temporal control over the reactions, generally fast[ii]) is powerful because the polymerizations could be carried out at room temperature or below, with minor risk of colloidal destabilization and using an external light source provides an external handle to control the polymerizations. In this context, the use of IR would side-step the limitations induced on shorter wavelengths by the light scattering caused by the nanoparticles formed, or by the direct absorption of the latter photons by the polymerization components (e. g. hybrid latexes containing UV-absorbing oxides, or pigments).
Coordinator : Jacques LALEVÉE
Scientific leader IS2M : Jacques LALEVÉE