Lab-on-a-chip technology is a rapidly growing research area. Joining together several disciplines, such as physics, biology and several instances of nanotechnologies. The aim of this research is mainly to produce chips that can do the same types of measurements as large lab equipment and measurement systems, but at a fraction of the size and cost. In this work a multifunctional measuring device have been developed. It can measure optical absorbance and fluorescence while performing a range of potentiometric techniques; including chronoamperometry, linear- and cyclic voltammetry. From all these measurements it is possible to calculate particle concentrations in fluid samples. The aim is to bring simpler and cheaper point of care devices to the public. Without larger losses in accuracy and reliability of the medicinal test. To do this our device is intended to be used with lab-chip, which are capable of amplifying the signals while reducing the sample size. Lab-chips could be used in several areas but the ones being designed with this device are made for biomedical purposes, applying suitable nanostructures and reagents to measure the presence of biomarkers. With these techniques, medicinal diagnostics can be made a few minutes after samples have been collected from patients. Much quicker and more direct than sending the samples to a lab and waiting hours if not days for the results. The measuring device or lab-chip reader will use two different lab-chips in the future. One that is optimised for optical absorbance and the other for fluorescence. Both will work with electrochemical measurements, but at present only the absorbance chip have been available for testing and that without any signal enhancing techniques. Assessment of the reader's capabilities was made with solutions of gold nanoparticles, TMB (tetramethylbenzidine), iron dissolved in PBS (Phosphate-buffed saline) and with a film made of PPV (Poly para-phenylenevinylene). The first two were used to test absorbance; while the iron and PBS have been used to test electrochemical system; and the PPV was coated on a glass substrate and used to test fluorescence. During the optical absorption test, it was found that the reader can distinguish between different concentrations of the various solutions. The results are promising and further removal of signal drifts will improve signals considerably. Fluorescence can be induced and measured with the device. This part of the system is, however, untested in general and future work will show if it is sufficient. The iron solution was tested with three different methods. chronopotentiometry, linear sweep voltammetry and cyclic voltammetry. It was however found that our measurements were distorted in comparison with the expected voltammogram for iron in PBS. Additional peaks were found in the voltammogram and it is believed that these are a result of oxidation of the electrodes on the lab-chip.

Health-care delivery in developing countries has many challenges because they do not have enough resources for meeting the healthcare needs and they lack testing lab infras- tructures in communities. It has been proven that Point-Of-Care (POC) testing can be considered as one of the ways to resolve the crisis in healthcare delivery in these com- munities. The POC testing is a mission critical processes in which the patient conduct tests outside of laboratory environment and it needs a secure communication system of architecture support which the research refers as POCT system Almost every ten years there will be a new radio access technology (RAT) is released in the wireless communication system evolution which is primarily driven by the 3GPP standards organisation. It is challenging to develop a predictable communication sys- tem in an environment of frequent changes originated by the 3GPP and the wireless operators. The scalable and expandable network architecture is needed for cost-effective network management, deployment and operation of the POC devices. Security mecha- nisms are necessary to address the specific threats associated with POCT system. Se- curity mechanisms are necessary to address the specific threats associated with POCT system. The POCT system communication must provide secure storage and secure com- munication to maintain patient data privacy and security. The Federal Drug Admin- istration (FDA) reports the leading causes of defects and system failures in medical devices are caused by gaps between the requirements, implementation and testing. The research was conducted, and technical research contributions are made to resolve the issues and challenges related to the POCT system. A communication protocol implemented at the application level, independent of radio access technologies. A new methodology was created by combining Easy Approach to Requirement Specifications (EARS) methodology and Use Case Maps (UCM) model which is a new approach and it addresses the concerns raised by the FDA. Secure cloud architecture was created which is a new way of data storage and security algorithms models were designed to address the security threats in the POCT system. The security algorithms, secure cloud architecture and the communication protocol coexist together to provide Radio access technology Independent Secure and Expandable (RISE) POCT system. These are the contributions to new knowledge that came out of the research. The research was conducted with a team of experts who are the subject matter experts in the areas such as microfluidics, bio-medical, mechanical engineering and medicine.

Lab‐On‐a‐Chip (LOC) or Micro Total Analysis System (μTAS) technology requires precise control of minute amounts of liquid. Moving liquids in small capillaries requires bulky expensive external pumps that defy the purpose of microfabrication. By integrating a micropump into the device, it allows the system to be transportable, reliable, energy efficient and inexpensive. Such a microsystem built on a chip has been designed to study separation by dielectrophoretic chromatography. Nanobeads were successfully separated and used separately to measure fluid velocity and study the electroosmosis effect. Cell or beads of different type can be trapped in this system. This system encompasses a solid‐state AC electroosmotic pump for the manipulation of liquid‐containing cells or molecules. AC Electroosmosis is the movement of induced charges over polarised electrodes created by a non‐uniform electric field. The charges undergo Coulomb forces and drag the fluid with their motion. This results in bulk flow over the electrodes. This micro pump is used in a LOC by fabricating the pump on two sides of a microfluidic channel. The transport of material from what can be an analyte to a cell is of critical interest. The described system in the second part of this thesis presents the advantage of having a defined number of droplets, each of which is a lab on chip. The paradigm is the droplet and therefore the vessel that carries the information. Surfaces are then the place of interaction with the vessel which carries the second aspect of this thesis. Several approaches have been investigated, in particular by enclosing the droplet between two slides in order to increase the change of contact angle under the presence of polarised electrodes. This system is known as EWOD (ElectroWetting On Dielectric). It follows the approach of modified Lippmann laws and the modification of the apparent contact angle and therefore the motion of the droplet. The lid is somewhat a problem and the possibility of using liquid dielectrophoresis to create a multitude of droplets of calibrated volume is an advantage, as it is harder to create fixed‐volume droplets with an open geometry by EWOD due to contact angle hysteresis.

Many functions in a lab-on-a-chip device such as heating, electrochemical sensing and electrophoresis require integration of microelectrodes. However, conventional techniques for microelectrode integration are either requiring expensive facilities, cleanroom environment or insufficient in resolution and microelectrode thickness. Microwires have also been integrated into LOC devices as microelectrodes. They are commercially available in a diversity of material. and diameter, with industrial production standard and mechanical strength comparable to bulk metal, which make them ideal candidate for microelectrode. Nonetheless a technique to integrate these microwires into complicated microelectrode patterns has not yet been developed. In this thesis, two microwire integration techniques based on xurography are developed for elastomer and rigid polymer. Copper, silver, platinum, carbon and Ni-Cr alloy microwires down to 15 µm with minimum spacing of 150 µm and controllable position in the height direction are successfully integrated. The microwire electrode can also be suspended in the middle of the microchannel with desired length and angle. Various applications are presented to demonstrate the versatility of the xurographic microwire integration process. / Thesis / Master of Applied Science (MASc)

Droplet-based microfluidics can be used to enhance stem cell-based therapy by creating cell-laden hydrogel encapsulations to increase engraftment and retention while providing protection from immune responses caused by the host environment. Current research involves gaining better control over therapeutic mechanisms and one focus is to understand the mechanisms behind cell egress. Control over egress is vital to determining how long cells remain in proximity to the therapeutic target. We propose a microfluidic platform capable of encapsulating cells in two subsequent steps in order to create a double emulsion structure around the cell. In this project, hydrogel-in-hydrogel microdroplets are successfully manufactured without the presence of an intermediate oil layer and are used to observe model NIH 3T3 cell egress. In studying cell egress from singly or doubly encapsulated microcapsules, we are able to better understand the mechanisms that drive egress. Specifically, we hypothesize that cells egress when close to the edge of the microcapsule. In a double emulsion, cells are naturally located away from the edge and closer to the center. Results show that double emulsion microdroplets significantly reduce cell egress but do not eliminate it.

Le suivi de la qualité de l'eau a été d'une grande importance depuis ces dernières décennies afin de trouver des solutions de contrôler la contamination de l'eau, induite en grande partie par les activités agricoles et industrielles. Bien que les méthodes conventionnelles, comme la chromatographie, sont des outils très précis et sensibles, un intérêt grandissant a été placé sur des techniques prometteuses qui peuvent être utilisées sur site, sont bas coût, et offrent la possibilité d'effectuer des analyses rapides. Le travail présenté ici est dédié au développement de composant Laboratoire sur Puce pour l'analyse de la toxicité de l'eau. Il consiste en un système portable pour la détection sur site et offre la possibilité d'une double détection complémentaire : optique et électrochimique. Comme la partie dédiée au capteur électrochimique a préalablement été validée, cette étude est focalisée sur l'implémentation d'un biocapteur électrochimique basé sur l'utilisation d'une algue, pour la détection de polluants dans l'eau. Le principe basique de détection consiste au suivi de changements de l'activité métabolique d'algues induits par la présence d'herbicides. La réponse de l'algue est différente pour chaque concentration d'herbicide dans un échantillon examiné. Deux herbicides sélectionnés affectent l'activité photosynthétique de l'algue et par conséquent, induisent des modifications dans la quantité des espèces électroactives produites par l'algue : O2, H2O2 et H3O+/OH-. Avant le développement du composant final type Laboratoire sur Puce, les principes de détection aussi bien que les matériaux d'électrode qui vont être intégrés, ont été validés en utilisant un type de composant plus simple, qui a été réalisé grâce aux technologies de fabrication silicium et qui a été caractérisé par des procédures plus simples. Une puce sur silicium contenant un microsystème électrochimique intégrant trois électrodes a été mis en place. Une fois validés, les matériaux de détection et les configurations choisis précédemment ont été utilisés pour la fabrication des composants Laboratoire sur Puce. Les composants Laboratoire sur Puce ont été ensuite utilisés pour des tests biologiques afin de détecter les herbicides d'intérêt. Une attention spéciale a été placée sur le suivi de O2 comme indicateur de la présence d'herbicide, étant donné que cet élément est le plus représentatif de modifications de l'activité métabolique. Un effet d'inhibition sur la photosynthèse, dépendant de la concentration de l'herbicide a été démontré. La détection de l'herbicide a été réalisée avec une grande sensibilité et sur une gamme couvrant la limite de concentration maximale acceptable imposé par le gouvernement canadien. / Water quality assessment has attracted wide attention during the last decades in order to find ways to control contamination of water bodies induced, in a big part, by agricultural and industrial activities. Although conventional techniques, such as chromatography are highly accurate and sensitive tools, increasing interest has been placed lately to powerful alternative techniques that can be used on field, are cost-effective and offer the possibility of conducting rapid analysis. The present work was therefore dedicated to the development of a lab-on-chip device for water toxicity analysis. It consists in a portable system for on-site detection and aims at offering the possibility of conducting double complementary detection: optical and electrochemical. Since the optical sensor is already validated, this study focused on the implementation of the algal-based, electrochemical biosensor for detection water contaminants. The basic detection principle consists in monitoring disturbances in metabolic activities of algae induced by the presence of the herbicides. Algal response is different for each herbicide concentration in the examined sample. The two selected herbicides affect algal photosynthetic activity and consequently induce modifications in the quantity of electroactive species, O2, H2O2 and H3O+/OH- ions related to pH, produced by algae. Prior to the development of the final lab-on-chip device, the detection principle as well as the electrode materials that were going to be integrated were validated using a simpler device that was implemented using a silicon-based fabrication technology and was characterized using simpler procedures. A silicon chip containing the integrated three-electrode electrochemical microsystem was fabricated. The performance of the microsystem was evaluated through electrochemical characterization and calibration was performed. Once validated, the aforementioned materials and configurations were used for the fabrication of the lab-on-chip devices. The lab-on-chip devices were further used in bioassays to detect the herbicides of interest. Special emphasis was placed on O2 monitoring as indicator of the presence of herbicide, as it is the element the most representative of variations in metabolic activities. A concentration-dependent inhibition effect of the herbicide on photosynthesis was demonstrated. Herbicide detection was achieved with a greater sensitivity and a range covering the limit of maximum acceptable concentration imposed by Canadian government.

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This text describes different aspects of the design of a Doctor-on-a-Chip device. Doctor-on-a-Chip is a DNA analysis system integrated on a single chip, which should provide all of the advantages that stem from the system integration, such as small sample volume, fast and accurate analysis, and low cost. The text describes all of the steps of the on-chip sample analysis, including DNA extraction from the sample, purification, PCR amplification, novel dielectrophoretic sorting of the DNA molecules, and finally detection. The overview is given of the technologies which are available to make the integration on a single chip possible. The microfluidic technologies that are used to manipulate the sample and other chemical reagents are already known and in this text they are analyzed in terms of their feasibility in the on-chip system integration. These microfluidic technologies include, but are not limited to, microvalves, micromixers, micropumps, and chambers for PCR amplification. The novelty in the DNA analysis brought by Doctor-on-a-Chip is the way in which the different DNA molecules in the sample (for example, human and virus DNA) are sorted into different populations. This is done by means of dielectrophoresis – the force experienced by dielectric particles (such as DNA molecules) when subject to a non-uniform electric field. Different DNA molecules within a sample experience different dielectrophoretic forces within the same electric field, which makes their separation, and therefore detection, possible. In this text, the emphasis is put on numerical modelling of the dielectrophoretic effect on biological particles. The importance of numerical modelling lies in the fact that with the accurate model it is easier to design systems of microelectrodes for dielectrophoretic separation, and tune their sub-micrometre features to achieve the maximum separation efficacy. The numerical model described in this text is also experimentally verified with the novel microelectrodes design for dielectrophoretic separation, which is successfully used to separate the mixture of different particles in the micron and sub-micron range.

Les microsystèmes intégrant des techniques microfluidiques offrent la possibilité de réaliser des analyses biologiques directement sur le site de prélèvement de l’échantillon. Ils ont pour objectifs notamment d’augmenter l’efficacité, la rapidité et l’accessibilité de ces tests. Pour développer efficacement un tel dispositif, un ensemble de critères doit être fixé tels que la limitation du coût, la portabilité, la simplicité d’utilisation et la précision des résultats. Un objectif de cette thèse est également de proposer un nouveau système portable permettant de répondre à un maximum d’applications. Pour cela, il convient d’intégrer et d’automatiser des protocoles biologiques complexes c’est-à-dire nécessitant l’ajout de plusieurs réactifs et des réactions en parallèle. A titre d’exemple, les tests ELISA sont abordés.Pour répondre à cette problématique, une technique innovante utilisant un matériau hyperélastique est combinée à une architecture X-Y. Des chambres étirables, permettant de calibrer et de mélanger des volumes compris entre 1 µL et une centaine de µL, sont ainsi réalisées. Différents protocoles sont intégrés et validés par ordre de complexité croissante dans des cartes microfluidiques en commençant par une gamme de dilution qui est la première étape pour la calibration des protocoles biologiques, puis un test enzymatique et un test ELISA homogène, avant d’aborder le test ELISA hétérogène qui est le protocole visé.Un démonstrateur permettant de piloter les cartes microfluidiques est ensuite présenté. Cette plateforme est générique et compatible avec les cartes microfluidiques développées. Enfin, pour automatiser complétement la mise en œuvre des protocoles, une nouvelle technique d’embarquement de réactifs liquide est proposée. / Microsystems utilizing microfluidic techniques offer the possibility to perform point-of-need biological analysis. An objective of these systems is to increase the efficiency, speed and accessibility of these analyses. In order to effectively develop this kind of device, a set of criteria must be established and adhered to. This set should address cost limitations, portability, user-friendliness, and accuracy of the results. Another objective is to propose a new portable system that has the capability to address as many applications as possible. To this end, complex biological assays with multiple steps and multiple reagents must be integrated and automated. ELISA is one such assay being considered.To deal with this issue, an innovative technique employs a hyper-elastic material joined to an X-Y architecture. The resulting chambers are flexible, thus allowing for calibration and mixing on the range of 1 µL to hundreds of µL. Several protocols are integrated and validated in microfluidic chips in order of increasing complexity. To start, a range of dilutions is performed, which is then used to calibrate biological assay. Next, an enzymatic assay and a homogeneous ELISA are integrated. Finally, heterogeneous ELISA, which is the aimed assay, is achieved.We present here a prototype to demonstrate the handling of the microfluidic chip. This platform is versatile and compatible with those that have been previously developed. Additionally, the introduction and integration of liquid reagents is proposed in order to completely automate the protocol.

A biosensor is an analytical device integrating a biological element and a physicochemical transducer that convert a biological response into a measurable signal. The advantages of biosensors include low cost, small size, quick, sensitivity and selectivity greater than the conventional instruments. Biosensors have a wide range of applications ranging from clinical diagnostics through to environmental monitoring, agriculture industry, et al. The different types of biosensors are classified based on the sensor device as well as the biological material. Biosensors can be broadly classified into (piezoelectric, etc.), electrochemical biosensors (potentiometric, amperometric, etc.), and optical types of biosensors (fiber optics, etc.). Here, we introduce a novel microfluidics-integrated biosensor platform system that can be flexibly adapted to form individual biosensors for different applications. In this dissertation, we present five examples of different emerging areas with this biosensor system including anti-cancer drug screening, glucose monitoring, heavy metal elements measurement, obesity healthcare, and waterborne pathogen DNA detection. These micro-biosensors have great potential to be further developed to emerging portable sensing devices especially for the uses in the developing and undeveloped world. At the last chapter, Raman spectroscopy applied to assess gestational status and the potential for pregnancy complications is presented and discussed. This technique could significantly benefit animal reproduction.