Conception et implémentation d'un décodeur dédié à un modulateur sigma-delta

Introduction aux convertisseurs analogique-numériques -- Le décodage dans les convertisseurs Sigma-Delta -- Formulation mathématique du processus de décodage développé -- Architecture du module de décodage dynamique

Laboratoire sur puce pour la séparation et détection des particules à base de diélectrophorèse à basse tension

Résumé Notre recherche est construite autour de la volonté de développer et d'élargir l'utilisation des laboratoires sur puce (LsP), d'y intégrer de nouvelles fonctions et de proposer des approches de modélisation plus rigoureuses. En effet, les travaux de pointe montrent que pour réaliser des modèles mimant le plus fidèlement possible les systèmes vivants, les LsP doivent évoluer des simples supports fonctionnalisés que sont les puces d'analyse et de séparation de l'ADN vers des systèmes intégrant davantage de fonctions. Pour ce faire, nous proposons tout d'abord un premier prototype d'un LsP comprenant des modules microélectroniques, microfluidiques, de communication radio fréquence et d'alimentation intégrée, pour la séparation des particules avec des validations in-vitro. Cette plateforme a pour objectif d'observer le comportement des particules face à une variation de la fréquence, de la phase ou de l'amplitude du champ électrique avec différentes architectures d'électrodes. De plus, étant programmable et reconfigurable, elle nous a permis de valider plusieurs concepts, notamment l'identification fréquentielle des micro et nanoparticules. Cette dernière représente notre principale contribution qui pourrait, éventuellement, ouvrir la porte à plusieurs recherches notamment celles portant sur l'identification des maladies neurodégénératives. Notre but étant d’offrir une grande flexibilité dans la modélisation, nous présentons une nouvelle approche pour modéliser les LsP dans laquelle le comportement des particules est modélisé en tenant compte de l'architecture des électrodes, des signaux appliqués et des propriétés biologiques du milieu. Cette première modélisation en son genre est une approche hybride combinant une modélisation par éléments finis à l’aide d’ANSYS et une implémentation d’un algorithme sur Matlab. Elle permet de calculer la position d'une particule dans un microcanal en se basant sur les résultats fournis par ANSYS. Cette modélisation présente de nombreux avantages dont notamment, la possibilité d’identifier l’emplacement d'une particule avec précision en 3D, en plus de valider la séparation des particules à travers toute la profondeur du microcanal, ce qui n'est pas possible en se basant uniquement sur les résultats expérimentaux. De plus, nous avons fabriqué le système complet avec une architecture 3D de 5 PCB, une plateforme microfluidique, un contrôle sans fil par Bluetooth et un bloc d'alimentation programmable et intégré dans un même microsystème. Toute la partie microélectronique du LsP a été implémentée sur une puce microélectronique fabriquée avec la technologie CMOS 0.18 um de TSMC. Quant à l'architecture microfluidique, elle a été fabriquée avec les procédé Sensonit et Lionix.----------Abstract Our research project is devoted to develop and extend the use of laboratories on chip (LoC), and to add to them new functions and more rigorous modeling techniques. Without a doubt, the state of art shows that, in order to create models that reflect living organisms best, LoCs need be more evolved systems that serve more functions than simple and limited-function DNA chips. To do so, we propose a first prototype of a Lab on Chip with microelectronic and microfluidic modules, and integrated radio-frequency communication and power supply to separate the different particles in the cerebrospinal fluid with validations done in vitro. The purpose of this platform is to observe the particles' behaviour when facing a change in the electric field's, frequency, phase, or amplitude, all this using different architectures of electrodes. Moreover, the platform is programmable and reconfigurable, which is important as it allows the validation of many concepts, such as the frequency separation of micro and nanoparticles. This platform actually represents our main focus in this research. We believe that it will eventually lead to many other research and medical advancements, such as identifying the source of many degenerative neurological disorders. We also came up with an innovative approach to give a greater flexibility to the modeling of LoCs. This approach consists of modeling the behaviour of particles based on the architectural design of the electrodes, the applied signals, and the biological properties of the medium. This first type of modeling is based on a hybrid approach between a Finete element modeling using ANSYS, and an algorithmic implementation on Matlab that makes it possible to calculate each particle's position in a micro canal based on the results provided by ANSYS. Such modeling has many advantages; for example, it can precisely identify the location of a particle in 3D, as well as separate the particles throughout the whole micro canal, all of which is not possible based on experimental results. Also, we built this system entirely with a 3D architecture of PCB, a microfluidic platform, a Bluetooth wireless controller, and a source of power supply integrated all in one microsystem. The whole microelectronic part of the LoC is put on a microelectronic chip made with the CMOS 0.18 um TSMC technology. As for the microfluidic architecture, it was fabricated using both the Sensonit and Lionix processes

Recent Advancements towards Full-System Microfluidics

Microfluidics is quickly becoming a key technology in an expanding range of fields, such as medical sciences, biosensing, bioactuation, chemical synthesis, and more. This is helping its transformation from a promising R&D tool to commercially viable technology. Fuelling this expansion is the intensified focus on automation and enhanced functionality through integration of complex electrical control, mechanical properties, in situ sensing and flow control. Here we highlight recent contributions to the Sensors Special Issue series called “Microfluidics-Based Microsystem Integration Research” under the following categories: (i) Device fabrication to support complex functionality; (ii) New methods for flow control and mixing; (iii) Towards routine analysis and point of care applications; (iv) In situ characterization; and (v) Plug and play microfluidics

High Throughput Microfluidic Rapid and Low Cost Prototyping Packaging Methods

In this work, 3 different packaging and assembly techniques are presented. They can be classified into two categories: one-time use and reusable packaging techniques. The one-time use packaging technique employs UV-based and temperature curing epoxies to connect microtubes to access holes, wire-bonding for integrated circuit connections, and silver epoxy for electrical connections. This method is based on a robust assembly technique that can support relatively high pressure close to 1 psi and does not need any support to strengthen the microfluidic architecture. Reusable packaging techniques consist of PDMS-based microtube interconnectors and anisotropic adhesive films for electrical connections. These devices are more sensitive and fragile. Consequently, Plexiglas support is added to the microfluidic structure to improve the electrical contact when anisotropic adhesive films are used, and also to strengthen the microfluidic architecture. In addition, a micromanipulator is needed to maintain tubes while using a thin PDMS layer to connect them to the access holes. Different PDMS layer thicknesses, ranging from 0.45-3 mm, are tested to compare the best adherence versus injection rates. Applied injection rates are varied from 50-300 μl/hr for 0.45-3 mm PDMS layers, respectively. These techniques are mainly applicable for low-pressure applications. However, they can be extended for high-pressure ones through plasma-oxygen process to permanently seal the PDMS to glass substrates. The main advantage of this technique, besides the fact that it is reusable, consists of keeping the device observable when the microchannel length is very short (in the range of 3 mm or lower)

Recent Advancements towards Full-System Microfluidics

Microfluidics is quickly becoming a key technology in an expanding range of fields, such as medical sciences, biosensing, bioactuation, chemical synthesis, and more. This is helping its transformation from a promising R&D tool to commercially viable technology. Fuelling this expansion is the intensified focus on automation and enhanced functionality through integration of complex electrical control, mechanical properties, in situ sensing and flow control. Here we highlight recent contributions to the Sensors Special Issue series called “Microfluidics-Based Microsystem Integration Research” under the following categories: (i) Device fabrication to support complex functionality; (ii) New methods for flow control and mixing; (iii) Towards routine analysis and point of care applications; (iv) In situ characterization; and (v) Plug and play microfluidics