« Retour

Jeandupeux Laure

Adjoint-e scientifique HES

Contrat principal

Adjoint-e scientifique HES

Haute Ecole Arc - Ingénierie
Espace de l'Europe 11, 2000 Neuchâtel, CH

BSc HES-SO en Microtechniques - Haute Ecole Arc - Ingénierie

Procédés de micro-fabrication et applications
BioMEMS et microfluidique
Projet P2
Travaux de Bachelor

En cours

I-CARE - Identification de tissus ovariens CAncéRogènes à l’aide de l’Endoscopie et oxymétrie colorimétrique in-situ

Rôle: Collaborateur/trice

Financement: Fonds HES-SO - Fond de recherche et d'impulsions - Programme du rectorat (REC)

Description du projet :

Nous proposons une méthode spectroscopique pour surveiller l'ablation chirurgicale des tumeurs ovariennes. Malgré les
améliorations apportées au diagnostic préopératoire, il est encore difficile de délimiter précisément les limites des tumeurs.
Les tissus cancéreux présentent un plus grand nombre de vaisseaux sanguins que les tissus sains, mais sont moins saturés
en oxygène. Ici, nous proposons l’oxymétrie pour mesurer le taux d'oxygène dans le tissu à analyser, sans prélever
directement d'échantillon en salle d'opération. L'hémoglobine oxygénée et l'hémoglobine désoxygénée possèdent des
coefficients d'absorption optiques différents, et donc il est possible de les discriminer par oxymétrie. Ces mesures se feront
avec des sondes à fibres optiques souples.

Equipe de recherche au sein de la HES-SO: Jeandupeux Laure , Laux Edith , Llera Miguel , Potty Philippe

Durée du projet: 01.11.2023 - 30.06.2024

Montant global du projet: 80'000 CHF

Statut: En cours

Terminés

TESS - ThermoElectric Sensors based on ionic liquids for biological applicationS

Rôle: Requérant(e) principal(e)

Financement: HES-SO

Description du projet :

Les réactions biochimiques sont d’une grande importance dans le domaine du test diagnostique. Parmi la multitude de réactions possibles, les réactions calorimétriques – dégageant ou consommant de l’énergie thermique – sont notamment présentes dans des tests immunologiques permettant de détecter certaines inflammations, des maladies comme Alzheimer ou certains cancers. La médecine personnalisée, ou encore les tests rapides, vers laquelle tend la société sera possible grâce à des dispositifs tels que les laboratoires sur puce permettant de détecter ces réactions.

Dans le cadre d’un projet européen, la HE-Arc Ingénierie a développé un microgénérateur thermoélectrique basé sur les liquides ioniques, qui produisent une puissance électrique quand ils sont soumis à un gradient de température. Ces liquides peuvent ainsi produire une tension de l’ordre de 1.5mV/K avec une seule jonction. Il est donc envisageable d’utiliser ces générateurs pour détecter des changements de température générés par une réaction biochimique calorimétrique en monitorant la tension.

Ce projet a pour but de d’obtenir une preuve de concept afin de voir les avantages, inconvénients et caractéristiques possibles d’un tel capteur, selon trois phases : l’adaptation du design du microgénérateur afin de le transformer en capteur, la mise en place d’un banc de test afin de mesurer la tension générée par de petites variations de température, et la validation du concept sur un dispositif microfluidique simulant un test de laboratoire sur puce.

Equipe de recherche au sein de la HES-SO: Jeandupeux Laure

Durée du projet: 01.03.2022 - 31.08.2023

Montant global du projet: 50'000 CHF

Statut: Terminé

Une nouvelle génération de sensors pour la détection du phosgène (PhoSensor)

Rôle: Collaborateur/trice

Financement: HES-SO

Description du projet :

Phosgene (COCl2) is a highly poisonous chemical weapon agent (CWA). Unlike other CWA whose production and use are internationally prohibited, several million tons of phosgene are produced all over the world each year because this compound is a valuable building block for the synthesis of various plastics, pesticides and pharmaceuticals. This represents a huge threat to public health and safety not only because of possible accidental leaking but also because of potential terrorist attacks. Thus, is of great importance to develop highly sensitive and selective sensors for phosgene in gas but also in liquid phase.
A number of phosgene sensors based on diamine or alcohol type sensing molecules are available but most of them have important limitations in terms of portability, selectivity, detection limit, costs and / or lifetime.
Recently, we discovered in a totally serendipitous manner, that a new compound, a carboxylic derivative of a chiral pinenepyridine compound (1 in the project description) reacts with traces of phosgene present accidentally in a sample. The resulting isoindolone type molecule is colored and luminescent. Some preliminary investigations were performed under the guidance of the internationally recognized Swiss institute for the protection of the population against nuclear, biological and chemical threats and dangers, known also as Spiez Laboratory, who provides worldwide services relating to arms control, protection measures, health and incident management. These investigations have shown very promising results: stable sensing molecule, very rapid sensing reaction, high selectivity, very low detection limit.
In the framework of this project we propose to investigate the use of a completely new sensing type reaction, never reported in literature, in order to develop a fluorescent / colorimetric portable sensor for phosgene and phosgene related products.
The chemists from HEIA will design and synthesize a library of compounds structurally related to parent compound 1. In the environmental conditions the sensor is expected to operate, these molecules will be benchmarked in terms of stability, selectivity, detection limit and cost projections. The best candidates will be selected and their synthetic route optimized.
Programme de recherche / Appel à projets 2021 2/24
The engineers from HE Arc will built up the appropriate sensor prototype as a portable device, in agreement with the requirements of the sensing system. Using their proven skills in microfluidics, microelectronics and sensors integration, they will start by encapsulating the sensing molecule in a high surface area material (made by electrospinning). Readout on the portable device will be done:
a) qualitatively by a change in color/fluorescence of the sensor fabric and
b) quantitatively by a compact optical readout made of a LED/filter/photodiode cost-effective setup.
The HES-SO consortium will work in close collaboration with the Spiez Laboratory who will test the sensing molecules (in the WP2) but also the sensor prototype (WP5) and help to establish contacts with potential interested end users from industry for commercial exploitation. Moreover, other very dangerous, phosgene related molecules to which only this specialized laboratory has access, molecules chemically compatible with the new sensing system proposed here, will be tested in Spiez.

Equipe de recherche au sein de la HES-SO: Jeandupeux Laure , Mamula Steiner Olimpia , Kämpfer Alexandra , Laux Edith

Durée du projet: 01.12.2021 - 30.06.2023

Statut: Terminé

PublicMask

Rôle: Collaborateur/trice

Requérant(e)s: Hengsberger Stefan, HEIA-FR - iRAP

Financement: HES-SO

Description du projet :

Facemasks have gained unexpected attention during the Covid-19 pandemic. The high and sudden demand of facemasks has caused a serious shortage during several weeks on the Swiss market. Additionally, entire cargo of facemasks coming from Asian countries had to be destroyed since they did not meet the minimum requirements. This experience underlines the importance that Europe must become more independent from Asian products in such exceptional conditions. Currently, the first decontainment phase is still ongoing. To avoid a new increase of the infection curve the public must accept to wear a facemask when the minimum social distancing cannot be respected. The use of facemasks on public places, during events like live concerts or demonstrations as well as on beaches will necessarily lead to facemasks that are thrown away in nature. Biodegradable disposable facemasks are therefore a first step to avoid an increasing pollution of the environment.
Currently two major projects in this field are ongoing in Switzerland, the HelloMask and the ReMask project. These projects primarily focus on a high protection for a wearer in the care sector who is potentially permanently exposed to dangerous viruses. The target group of our PublicMask project are people who are less exposed to viruses and who make a less responsible use of the facemask.
In the context of our PublicMask project stakeholders in the field of biomedical engineering, industrial chemistry, plasturgy and nanotechnology will collaborate. The goal is to develop a biodegradable filter for a use in disposable facemasks. This filter will be fabricated by electro-spinning. This method allows for a fabrication of thin continuous polymer fibers by accelerating a polar polymer/solvent mixture with an electric field. A dense network with fibers of less than 1 micrometer in diameter can be obtained what is efficient to absorb particles of the typical size of viruses.
The innovative part of this project is the development of biodegradable filters using a polyester-amide grade that has been developed “in-house” by the ChemTech institute (HEIA-FR). ChemTech will tune the polymer/solvent mixtures to achieve a viscosity that is adapted to the electro-spinning process. The medical devices group (HE-ARC) will set up and optimize the electro-spinning process in a first step with a solvent-based polymer solution. A filter test stage will be developed by iRAP (HEIA-FR). The filter must fulfill two main requirements, high virus absorption and a high air transmission. For the efficiency test the filter material will be exposed to a continuous air flow saturated with plastic microparticles. The goal is the production of a biodegradable filter that performs at least as well as the Polypropylene based filter of standard disposable masks. A biodegradation test of the filter will be developed and demonstrated. Furthermore, the fabrication of the filter applying melt-spinning will be tested, what is an economically and ecologically interesting process. Melt-spinning allows for producing fibers of molten polymer what avoids the use of (toxic) solvents.
The project results will be valorized by publications, newsletter, conference contributions and bilateral contacts with companies in the textile sector. The goal is to define follow-up projects aiming at integrating this new type of filter in disposable masks.

Equipe de recherche au sein de la HES-SO: Jeandupeux Laure , Nogueira Matos Tatiana Filipa , Chatelain Nina , Cattaneo Alessandro , Albergati Luce , Sciboz Pierre-Louis

Partenaires académiques: Hengsberger Stefan, HEIA-FR - iRAP; Marti Roger, HEIA-FR - ChemTech; Fiorucci Gianni, HE-Arc Ingénierie - Medical Device Group

Durée du projet: 01.01.2021 - 30.06.2022

Statut: Terminé

MAGENTA - MAGnetic nanoparticle based liquid ENergy materials for Thermoelectric device Applications

Rôle: Collaborateur/trice

Financement: H2020

Description du projet :

Today, much of world’s consumed energy is lost to waste heat through all levels of human activity. For example, thermal loss consists 20 to 50 % of total energy consumption across different industrial sectors and as high as 60-70% in current gasoline and/or diesel powered. If even a small fraction of ‘waste-heat’ could be converted into more useful forms of energy (e.g., electrical, mechanical, etc.), it would result in tremendous savings to global energy consumption.

In the MAGENTA (MAGnetic nanoparticle based liquid ENergy materials for Thermoelectric device Applications) H2020 project we are developing brand new thermoelectric materials based on ionic ferrofluids; i.e., colloidal dispersions of magnetic nanoparticles in ionic liquids. It is an inter-disciplinary and cross-sector R&D project combining concepts and techniques from physics, chemistry and electrochemistry with an active participation from industrial partners. As its final products, MAGENTA will offer novel liquid thermoelectric materials that are versatile, cost-effective and non-toxic to assist the economically and environmentally sustainable energy transition in Europe.

Equipe de recherche au sein de la HES-SO: Jeandupeux Laure

Durée du projet: 01.01.2017 - 30.08.2021

Url du site du projet: https://www.magenta-h2020.eu/

Statut: Terminé

Lentilles liquides à focus variable

AGP

Rôle: Collaborateur/trice

Requérant(e)s: VS - Institut Systèmes industriels, Geiser Martial, VS - Institut Systèmes industriels

Financement: HES-SO Rectorat

Description du projet : The project deals with the manufacturing of tunable lenses for smart imaging. It enables a potential application in ophthalmology for intraocular lens replacement which could be tuned by ciliary muscle. A lot of research is done by academy and industry to find a simple way to mimic the eye which is able tofocus from short distance to infinity by accommodation. Tuneable lenses is one possible answer to that quest. HES-ARC and HES-SO Valais are joining their efforts to build an iterative closed loop between fabrication and testing in order to apply the final results to a smart imaging system which would mimic the eye with multispectral illumination. Within a prior FP7 project, we successfully demonstrated the tunability of a lens by using a large drop of liquid encapsulated between a highly transparent elastic substrate and a sheet of Parylene. A highly asymmetric lens could be realised, whereby a close to human's eye property was demonstrated. However, drop formation was not mastered and reproducibility was difficult. The project smart-lens wants to pick up the challenge to master the dispensing of the liquid and to further optimise lens shape, so that it could be used in a stand-alone portable multi-spectral imaging system able to correct on-the-fly achromatic error and behave like the human eye to magnify an object by bringing it as close to the eye as possible. HES-ARC will build the lenses in which accommodation (change of focal length) will be performed by squeezing the lens appropriately with a driver. This one will be small in order to make the lens favourable to system integration. HES-SO Valais with there expertise in ophthalmology and lens system, will build a versatile system to assess optical imaging in the full imaging field at different tuned position. A feedback between optical quality and fabrication is foreseen in order to achieve high reproducibility and imaging quality. We will demonstrate the potential of our lenses through our smart imaging system built within this project. Demonstration will be done to many different types of industry such as Omnimedica (beauty care), Cima-Italy (cash handling), IDIAP (biometric recognition), Süssoptik (lens fabrication), etc.

Equipe de recherche au sein de la HES-SO: Walpen Olivier , Aellen Thierry , Amoos Serge , Farine Brunner Sophie , Geiser Martial , Broggini Christiane , Cséfalvay Catherine , Prieur Claudio , Ramseyer Stephan , Berthouzoz David , Truffer Frédéric , Hochstrasser Eric , Schaller Renaud , Laux Edith , Jeandupeux Laure , Mabillard Eric

Partenaires académiques: VS - Institut Systèmes industriels; Microtechnologies appl.; Geiser Martial, VS - Institut Systèmes industriels

Durée du projet: 01.11.2015 - 31.01.2018

Montant global du projet: 200'000 CHF

Statut: Terminé

Intégration d'un capteur permettant le suivi en continu de substances thérapeutiques dans le sang - Diagnostic Biochips - Projet DB-2015-003

AGP

Rôle: Collaborateur/trice

Requérant(e)s: VS - Institut Systèmes industriels, Roduit Pierre, VS - Institut Systèmes industriels

Financement: HES-SO Rectorat

Description du projet : Lors de traitements médicamenteux à l'hôpital tels que les chimiothérapies ou les anesthésies, les patients sont soumis à des doses très élevées de la substance thérapeutique pendant de longues durées qui peuvent aller jusqu'à plusieurs jours lors de cancers. Les concentrations du médicament dans le sang peuvent alors considérablement varier et atteindre des niveaux entraînant des effets secondaires importants voire fatals. Idéalement, les doses de médicament devraient être continuellement adaptées pour éviter ces pics et ainsi fortement atténuer les effets secondaires, mais ceci nécessiterait des analyses sanguines régulières (typ. tous les 5-15 minutes), ce qui n'est actuellement pas possible pour des raisons logistiques. Un système de mesure continu rendrait possible un tel suivi avec la possibilité d'éventuellement corriger le dosage de manière automatique. Dans le cadre du projet SupraDiag, des bio-senseurs supramoléculaires sont en cours de développement dont la fluorescence est modulée par la présence de substances actives de chimiothérapies. L'objectif de ce nouveau projet est d'intégrer cette technologie dans un démonstrateur permettant de faire le suivi quantitatif de médicaments directement dans le sang. Ce projet extrêmement interdisciplinaire aura pour but de régler tous les problèmes importants qu'il reste à résoudre pour avoir un démonstrateur portable: - Développement d'un système micro-fluidique pour le prélèvement et le transfert de l'échantillon vers une micro-chambre contenant les bio-senseurs et pour le lavage de celle-ci après la mesure, - Adaptation des bio-senseurs supramoléculaires aux mesures en continu dans le sang, - Insertion des bio-senseurs dans des hydrogels protecteurs permettant de ne laisser diffuser que les petites molécules, - Conception de revêtements anti-biofouling, - Développement de l'optique intégrée qui permettra de mesure le taux de fluorescence émise par les bio-senseurs, - Développement de l'électronique de contrôle et de mesure, - Développement de la partie communication sans fils qui permettra d'exporter la valeur mesurée du capteur. Ce projet pourra profiter des technologies développées dans le cadre du programme durant les projets SmartH2OGel (hydrogels), SupraDiag (bio-senseurs supramoléculaires) et MiniBioDet (modification de surfaces). L'appareil de suivi de substances thérapeutiques développé dans ce projet sera le démonstrateur prototypique d'une nouvelle génération d'instruments de médecine personnalisée.

, , , , , , , , , , , , , , , , , , Equipe de recherche au sein de la HES-SO: Walpen Olivier Aellen Thierry Farine Brunner Sophie Kämpfer Alexandra Condemi Enrico Geiser Martial Broggini Christiane Cséfalvay Catherine Prieur Claudio Truffer Frédéric Hochstrasser Eric Simalatsar Alena Marti Roger Segura Jean-Manuel Laux Edith Jeandupeux Laure Pfeifer Marc Emil Roduit Pierre Jacquemettaz Pascal

Partenaires académiques: VS - Institut Systèmes industriels; Microtechnologies appl.; VS - Institut Technologies du vivant; FR - EIA - Institut ChemTech; Roduit Pierre, VS - Institut Systèmes industriels

Durée du projet: 01.01.2016 - 31.12.2017

Montant global du projet: 250'000 CHF

Statut: Terminé

Thermoblankets for energy harvesting systems using Thermoelectric Generators

AGP

Rôle: Collaborateur/trice

Requérant(e)s: Micro et nano systèmes, Keppner Herbert, Micro et nano systèmes

Financement: Swiss Space Center EPFL

Description du projet : Financed by Swiss Space Center

Equipe de recherche au sein de la HES-SO: Journot Tony , Grange David , Kämpfer Alexandra , Kissling Jean-Michel , Prieur Claudio , Laux Edith , Jeandupeux Laure

Partenaires académiques: Micro et nano systèmes; Keppner Herbert, Micro et nano systèmes

Durée du projet: 30.06.2015 - 30.11.2015

Montant global du projet: 20'000 CHF

Statut: Terminé

PARYLENS

Rôle: Collaborateur/trice

Financement: EU FP7

Description du projet :

The main goal of the project PARYLENS is to develop the next generation optical devices, based on an innovative and reliable concept inspired by natural optical systems such as the human and the fly eyes. We propose the following devices to the European citizen and industry: 1) tuneable lenses 2) truly accommodative intraocular lenses 3) bistable flexible displays The development of those devices relies on recent advances in nanotechnology combined with the patented SOLID (Solid On Liquid deposition) process, which offers the possibility to grow a stable solid layer directly onto a liquid, such that the solid uniformly replicates and encapsulates the liquid template. When using the polymer Parylene as solid layer, the resulting interface is perfectly smooth and the liquid template remains unaffected, which is ideal for optical applications. Parylene is stable, biocompatible, highly transparent, and can be deposited in a one-step process also on liquids. PARYLENS proposes to develop low cost yet high quality, reliable smart devices. The actuation of the tuneable lenses will rely on Parylene-based electroactive polymers and liquid crystals. Tuneable lenses are expected to have an impact on the consumer electronics market (mobile phones, cameras, etc) in addition, the development of low actuation voltages tuneable lenses will profit to the biomedical devices market (artificial eyes, endoscopes, etc). The truly accommodative intraocular lenses will closely mimic the structure and shape of the crystalline lens of the human eye. They will also prevent inflammation and infections. The structure of microlens arrays will be used to develop flexible bistable liquid crystals displays. The consortium is well balanced (12 partners from 8 countries) and goes for full complementarity. It comprises 4 SMEs, 3 universities and 4 research centres. Together they will make this ambitious multidisciplinary project a reality.

Equipe de recherche au sein de la HES-SO: Jeandupeux Laure

Durée du projet: 01.10.2010 - 30.09.2013

Statut: Terminé

Multiparametric of engineered tissues from embryonic stem cells (ESCs) : tools for "Human-based in vitro testing systems" and "organ replacement".

AGP

Rôle: Collaborateur/trice

Requérant(e)s: hepia inSTI

Financement: HES-SO Rectorat

Description du projet : The main goal of the present project is to create biologically inspired artificial micro-organs from embryonic stem cells to mimic some features of a complex organism. The expected outcome of this project is the development of a "Multi-Organs-on-a-Chip" platform. This technology will serve as the base for the construction of biochips for in vitro drug and toxicological screenings as well as to design biomedical devices that will help to restore or replace organ functions in the future.

Equipe de recherche au sein de la HES-SO: Walker Anne , Walpen Olivier , Bourquin Stéphane , Trinchan Dominique , Andlauer Wilfried , Geiser Martial , Banakh Oksana , Cséfalvay Catherine , Ramseyer Stephan , Bisoffi Fabrice , Truffer Frédéric , Gex-Fabry Patrick , Brack Charles , Triscone Gilles , Charmet Jérôme , Passeraub Philippe , Schnyder Bruno , Eusèbe Hervé , Stoppini Luc , Duay Valérie , Laux Edith , Jeandupeux Laure

Partenaires académiques: 519,Economie d'entreprise; Microtechnologies appl.; VS - Institut Technologies du vivant; hepia inSTI

Durée du projet: 01.09.2009 - 31.01.2012

Montant global du projet: 550'000 CHF

Statut: Terminé

2023

Tunable and biodegradable poly(ester amide)s for disposable facemasks

Article scientifique ArODES

Esteban Alvarez Seoane, Alessandro Cattaneo, Fabien Neuenschwander, Lucien Blanchard, Tatiana Nogueira Matos, Laure Jeandupeux, Gianni Fiorucci, Maryam Tizgadam, Kelly Tran, Pierre-Louis Sciboz, Luce Albergati, Jérôme Charmet, Roger Marti, Stefan Hengsberger

Macromolecular Materials and Engineering, 2300375

Lien vers la publication

Résumé:

The widespread use of disposable facemasks during the COVID-19 pandemic has led to environmental widespread concern due to microplastic pollution. Biodegradable disposable facemasks are a first step to reducing the environmental impact of pandemics. In this paper we present high-performance facemask components based on novel poly(ester amide) (PEA) grades synthesized from bio-sourced materials and processed into non-woven facemask components. PEA based polymers present an excellent compromise between mechanical performance and biodegradability. Importantly, the properties of the PEA can easily be tuned by changing the ratio of the ester and amides, or variation of diol and diacid part. We synthesized seven polymers which we optimized for biodegradability and processability. Among them, two grades combined electrospinning process compatibility with full degradation within 35 days, using a normalized biodegradation test. The ultra-thin filters thus developed were evaluated for performance on a custom-made characterization bench. The filters achieved a microparticle capture efficiency and breathability comparable to commercial filters. Another PEA grade was optimized to reach optimal visco-thermal properties that made it compatible with solvent-free melt-spinning process as demonstrated with continuous fibres production. Overall, our environmentally friendly solution paves the way for the fabrication of high-performance fibres with excellent biodegradability for the next generation facemasks.

2020

Assembly of Liquid-based thermoelectric generator modules based on amine bonding

Article scientifique ArODES

Laure Jeandupeux, Edith Laux, Claudio Prieur, Philippe Potty, Herbert Keppner

Materials Today: Proceedings, 2021, vol. 44, Pt. 4, pp. 3494-3499

Lien vers la publication

Résumé:

In the previous years, it has been shown that ionic liquids (IL) are good candidates as base material for thermo-electric generators (TEG). Having identified promising ILs, the next step is building a module integrating those liquids and enabling its use with consumer devices. To keep the flexibility given by a liquid TEG, all the involved materials must be flexible. A TEG is composed of three different layers: 1) the bottom electrode foil, 2) a core foil, containing cavities with liquids, and 3) the top electrode foil. The core foil must be flexible, tight, easily shaped and must exhibit a low thermal conductivity. Inspired by microfluidics, polydimethylsiloxane (PDMS) was chosen. The electrode foils have to withstand metal coating and patterning, must be flexible while retaining electrical conductivity, and must not react with the liquids. Unfortunately, PDMS is not easily bonded to another polymer. Moreover, hermetic sealing of the liquids in a cavity while keeping the contact with the electrode is critical. The TEG being serial connected, if one junction fails the entire TEG fails. In this paper, we demonstrate a way to create the module first by using amine-based bonding of the liquids-accepting housing, and then filling the core cavities with liquids featuring different Seebeck coefficients, using a home built vacuum chamber. The results on bonding and filling are encouraging; they ensure tightness of all the 100 TEG contacts between ILs and electrodes. A Seebeck coefficient (SE) of 1 mV∙K−1 was measured, which is inferior to the expected value and thus asking for multiple improvements. However, the results must rather be seen as a proof of concept, especially concerning the sealing of the liquid, and as a step in the manufacturing process of highly integrated liquid-containing devices.

Impact of organic solvents in combination with redox-couples on magnitude of seebeck coefficient, and electrical current in thermoelectric generators

Article scientifique ArODES

Edith Laux, Laure Jeandupeux, Alexandra Kämpfer, Martin Hofmann, Philippe Potty, Herbert Keppner

Materials Today: Proceedings, 2021, 44, 4, 3489-3493

Lien vers la publication

Résumé:

In previous work it was shown that Ionic Liquids as active substances in thermoelectric generators have the potential to reduce the thermal conductivity as compared to Solid State materials used in conventional TEGs. Furthermore, it was observed that the Seebeck coefficient could be significantly increased. After a large variety of experiments, it appears that the remaining bottleneck coming to high performance TEGs is, first finding ILs with increased negative Seebeck coefficient, and, second sufficient current extraction. Looking at the current it appears, that higher extractions for a given redox-couple concentration are favoured at reduced viscosity. On the way to explore the effect of viscosity-induced current limitation, in a first step, the Ionic liquids are substituted by a low-viscosity organic solvent such as propylene carbonate (PC). The results showed that, indeed, the thermo-current increases significantly. It was further found that the Seebeck coefficient (SE) using PC exhibited values as high as 1.7 mV/K. Such high values were in previous work rather attributed to the use of ionic liquids. Surprisingly, by adding up to 10% of water to PC, the increased current allowed doubling the power, compared to pure PC. The paper studies the effect of combinations of solvent and redox-couples and tries to correlate the effect of water in PC looking at physical properties such as viscosity, but also the effects of charged carrier-attachment at the electrodes.

2018

Development of thermoelectric generator based on ionic liquids for high temperature applications

Article scientifique ArODES

Edith Laux, Stefanie Uhl, Nicolas Gauthier, Laure Jeandupeux, Herbert Keppner, Pilar Pérez López, Pauline Sanglard, Ennio Vanoli, Roger Marti

Materials Today: Proceedings, 2018, Vol. 5, No. 4, pp. 10195-10202

Lien vers la publication

Résumé:

Current, Seebeck-coefficients (SE) and maximal power output (Pmax) of thermoelectric generators using Ionic Liquids (ILs) were measured to determine the optimal temperature window for their use as thermoelectric generators (TEGs) in the range between room temperature (RT) and 300°C. The IL was sandwiched in a thermoelectric cell between a heated and a cooled electrode, allowing temperature-dependent current, voltage, and power-output characterization. Dissolving redox-couples (e.g. I2/I-) enables charge transfer from the IL to the electrode. It was found, that protic ILs degraded irreversibly at 140°C. Aprotic ILs, however, in combination with LiI/I2 redox couples exhibit higher temperature stability being finally limited either by redox-couple-electrode reactions, by temperature-induced redox couple degradation or by reaching at the boiling point at about 280°C. ILs being solid at room temperature could successfully be activated, as soon as at least the hot electrode of the set-up was heated above the melting point (m.p.) of the IL. As a striking observation, the thermo-voltage (linked to the SE) changes the sign as soon as the cold electrode was kept below the m.p. when Ethylammonium tetrafluoroborate (EA BF4) was used. Another IL, Tetrabutylammonium tetrafluoroborate (TBA BF4) exhibited in the full temperature range negative SE as high as 7 mV/K.

2016

Red blood cell phase separation in symmetric and asymmetric microchannel networks :

Article scientifique ArODES

effect of capillary dilation and inflow velocity

Francesco Clavica, Alexandra Kämpfer, Laure Jeandupeux, Dominik Obrist

Scientific reports, 2016, article no. 36763

Lien vers la publication

Résumé:

The non-uniform partitioning or phase separation of red blood cells (RBCs) at a diverging bifurcation of a microvascular network is responsible for RBC heterogeneity within the network. The mechanisms controlling RBC heterogeneity are not yet fully understood and there is a need to improve the basic understanding of the phase separation phenomenon. In this context, in vitro experiments can fill the gap between existing in vivo and in silico models as they provide better controllability than in vivo experiments without mathematical idealizations or simplifications inherent to in silico models. In this study, we fabricated simple models of symmetric/asymmetric microvascular networks; we provided quantitative data on the RBC velocity, line density and flux in the daughter branches. In general our results confirmed the tendency of RBCs to enter the daughter branch with higher flow rate (Zweifach-Fung effect); in some cases even inversion of the Zweifach-Fung effect was observed. We showed for the first time a reduction of the Zweifach-Fung effect with increasing flow rate. Moreover capillary dilation was shown to cause an increase of RBC line density and RBC residence time within the dilated capillary underlining the possible role of pericytes in regulating the oxygen supply.

2015

Solid on liquid deposition, a review of technological solutions

Article scientifique ArODES

Alexandra Kämpfer, Edith Laux, Laure Jeandupeux, Jerome Charmet, Roland Bitterli, Chiara Botta, Yves Rebetez, Oksana Banakh, Herbert Keppner

Microelectronic Engineering, 2014, vol. 14, pp. 467-279

Lien vers la publication

Résumé:

Solid-on-liquid deposition (SOLID) techniques are of great interest to the MEMS and NEMS (Micro- and Nano Electro Mechanical Systems) community because of potential applications in biomedical engineering, on-chip liquid trapping, tunable micro-lenses, and replacements of gate oxides. However, depositing solids on liquid with subsequent hermetic sealing is difficult because liquids tend to have a lower density than solids. Furthermore, current systems seen in nature lack thermal, mechanical or chemical stability. Therefore, it is not surprising that liquids are not ubiquitous as functional layers in MEMS and NEMS. However, SOLID techniques have the potential to be harnessed and controlled for such systems because the gravitational force is negligible compared to surface tension, and therefore, the solid molecular precursors that typically condense on a liquid surface will not sediment into the fluid. In this review we summarize recent research into SOLID, where nucleation and subsequent cross-linking of solid precursors results in thin film growth on a liquid substrate. We describe a large variety of thin film deposition techniques such as thermal evaporation, sputtering, plasma enhanced chemical vapor deposition used to coat liquid substrates. Surprisingly, all attempts at deposition to date have been successful and a stable solid layer on a liquid can always be detected. However, all layers grown by non-equilibrium deposition processes showed a strong presence of wrinkles, presumably due to residual stress. In fact, the only example where no stress was observed is the deposition of parylene layers (poly-para-xylylene, PPX). Using all the experimental data analyzed to date we have been able to propose a simple model that predicts that the surface property of liquids at molecular level is influenced by cohesion forces between the liquid molecules. Finally, we conclude that the condensation of precursors from the gas phase is rather the rule and not the exception for SOLID techniques.

2022

Production and viability of encapsulated bacterial-fungal consortia for delivery in soil

Conférence ArODES

Alexandra Kämpfer, Edith Laux, Laure Jeandupeux, T. Nogueira-Matos, A. Manimala, Nina Châtelain, Claudio Prieur, Cristina Martin-Olmos, Isha Hashmi, C. Hyde, C. Ruiz, Pilar Junier, Saskia Bindschedler

Proceedings of 26th International Conference on Miniaturized Systems for Chemistry and Life Sciences, 23-27 October 2022, Hangzhou, China

Lien vers la conférence

Résumé:

In this study, we present a novel type of microfluidics-based formulation for the delivery of microbial control agents (mBCAs) in soil, where bacterial cells and fungal spores are directly combined into millimeter-sized alginate capsules. This process resulted in the reproducible production of 500 μm sized beads in a good throughput for this type of biofluid (up to 48 beads/min). A subsequent chitosan coating (1-2 μm-thick) provided a good storage stability at 3 months, with 100% microcapsules containing viable fungal biomass and 60-80% with viable bacterial cells depending on the species. This novel formulation was tested both in the greenhouse and on-farm with lettuces, and encapsulated microbial biomass had a more prominent effect on crop growth and yield, as compared to their delivery as a liquid suspension.

2019

Assembly of Liquid-based Thermoelectric Generator Modules Based on Amine Bonding

Conférence

Oral presentation and Proceedings Paper

Jeandupeux Laure

European Conference on Thermoelectrics ECT 2019, 23.09.2019 - 25.09.2019, Chypre

Lien vers la conférence

Résumé:

In the previous years, it has been shown ionic liquids (IL) are good candidates as base material for thermo-electric generators (TEG) [1]. Having identified potential IL, the next step is building a module integrating those liquids. To keep the flexibility given by a liquid TEG, the involved materials should also be flexible.
A TEG is composed of three different layers: 1) the bottom electrode foil, 2) the body, containing cavities with p- and n-type liquids and 3) the top electrode foil. The body must be flexible, tight, and easily shaped. Inspired by microfluidics, polydimethylsiloxane (PDMS) was chosen. The electrode foils have to withstand metal coating and patterning, must be flexible while retaining electrical conductivity, and must not react with the liquids.
Unfortunately, PDMS is not easily bonded to another polymer. Moreover, sealing the liquid in a cavity and keeping the contact with the electrode is complex.
In this paper, we will demonstrate a way to create the module first using amine bonding [2], and then filling the body cavities with liquid using a customized vacuum chamber. With this technique, only four steps are required: 1) coating the electrode foils with an amine, 2) activate both the amine-treated surface and PDMS with oxygen plasma and put the two in contact, 3) put the assembly in a vacuum chamber, 4) pour the liquid to fill the cavities. This ensures perfect contact between IL and electrodes. Electrical and mechanical characterization was performed on a module. The results will be shown in this paper.
[1] “Aspects of Protonic Ionic Liquid as Electroyte in Thermoelectric Generators”, Laux et al, JEM, 2016, 45, 3383-3389
[2] “A facile route for irreversible bonding of plastic-PDMS hybrid microdevices at room temperature”, Tang et al, Lab Chip, 2010, 10, 1274–1280

Réalisations

PEOPLE@HES-SO Annuaire et Répertoire des compétences

Jeandupeux Laure

Adjoint-e scientifique HES

Adjoint-e scientifique HES

PEOPLE@HES-SO
Annuaire et Répertoire des compétences