Magnetic Bearing Proposal Design for a General Unbalanced Rotor System enhanced because of using sensors/actuators based in nanostructures

Rotor systems need bearings in order to keep uniformity of rotational movement transmission. However, bearingsgenerate friction and energy losses due to heating transmisssion through the friction; for this reason, mechanicak bearings are replaced by magnetic bearings owing to avoid energy losing because of friction. We designed Active Magnetic Bearings (AMB) to transmit rotational movement from source of movement (motor) through the rotor to the movement receptor (such as a conveyor belt). Magnetic Bearings need accuracy during System Identification process and a sophisticated control algorithm to get an uniform rotation movement transmission. In this work also it was analyzed and proved by simulations that Active Magnetic Bearings composed with sensors /actuators based in nanostructures are faster and robust compared with AMB based in traditional sensors/actuators. It because, nanostructures receive and send signals better way tan traditional sensors/actuators, because of high oredered nanoarrays improve sensor/actuator properties

Palladium-based Nanoplasmonics for Ultrafast and Deactivation-Resistant Hydrogen Detection

In the hydrogen economy scenario, hHydrogen gas is ispotential to be the main energy carrier in the hydrogen economy scenario in the upcoming future. It receives much attention since the reaction with oxygen generates electricity and produces only clean waterhydrogen is attractive as energy carrier since the energy produced by its reaction with oxygen only producesleaves water as by-product. However, \ua0hHydrogen , however, is flammable when mixed within ambient air even at low concentration, i.e. above 4 vol.%. Therefore, safety systems areis mandatory to monitor and prevent any leaks. The However, existing hydrogen sensor technology today, unfortunately, has not been able to passdoes not meet the stringent future safetyperformance targets for safety sensors standard.Motivated by thise safety issuefactat, in this thesis we I exploit the localized surface plasmon resonance (LSPR) of palladium (Pd)Pd and Pd-alloy nanoparticles to buildin the quest to develop next generation optical based hydrogen sensors. The uUnique features of an optical sensor among with respect to the other types are the inherent free-of-spark-free operation (thus safer), the possibility to perform a remote readout by light and the possibility forof a multiplexing. Specifically, I PalladiumPd, however, has limitations which hinders the hydrogen sensor to meet the requirement.My thesis reportsIn this thesis I focus onreport two key aspects related to the hydrogen sensor challenge: (i) the \ua0development of the palladiumPd-alloy based nanoplasmonic sensors that are both deactivation resistant and meet the stringent response time target, and (ii) the fundamental studies onunderstanding of nanoparticle-hydrogen interactions in the presence of different coatings. the hydrogen-palladiumPd nanoparticleAs the key results, I have developed two different types of plasmonic hydrogen sensor platforms either based on a PdAuCu ternary alloy or utilizing thin polymer film coatings. They exhibit exceptional deactivation resistance towards poisoning gases like carbon monoxide or nitrogen dioxide, and they meet the most stringent sensor response time target defined by the US Department of Energy. Furthermore, I have devised generic design rules for the optimization of plasmonic hydrogen sensor detection limits based on fundamental understanding, and systematically characterized the impact of surfactant molecules widely used in colloidal synthesis of Pd nanocrystals on their interaction with hydrogen gas. All in all, . The former implementation aspect includes two different strategies to optimize the sensor: (i) Au and Cu alloying and (ii) polymer (PMMA, PTFE) coating. The later fundamental aspect covers two studies on: (i) the correlation between the absorbed hydrogen and the optical response correlation and (ii) the (de)hydrogenation of surfactant/stabilizer-coated nanoparticle.Finally, weWe \ua0managed to achieve excellent hydrogen sensor performance that meets the strict demand and we acquired deeper insight on the hydrogen sensing mechanism which is important for the sensor design. tThese findings hopefully contribute to the safety aspect ofa safer hydrogen economy safety aspect and enable wider applicationsin the future

Polymer-Nanoparticle Hybrid Materials for Plasmonic Hydrogen Detection

Plasmonic metal nanoparticles and polymer materials have independently undergone rapid development during the last two decades. More recently, it has been realized that combining these two systems in a hybrid or nanocomposite material comprised of plasmonically active metal nanoparticles dispersed in a polymer matrix leads to systems that exhibit fascinating properties, and some first attempts had been made to exploit them for optical spectroscopy, solar cells or even pure art. In my thesis, I have applied this concept to tackle the urgent problem of hydrogen safety by developing Pd nanoparticle-based “plasmonic plastic” hybrid materials, and by using them as the active element in optical hydrogen sensors. This is motivated by the fact that hydrogen gas, which constitutes a clean and sustainable energy vector, poses a risk for severe accidents due to its high flammability when mixed with air. Therefore, hydrogen leak detection systems are compulsory in the imminent large-scale dissemination of hydrogen energy technologies. To date, however, there a several unresolved challenges in terms of hydrogen sensor performance, whereof too slow sensor response/recovery times and insufficient resistance towards deactivation by poisoning species are two of the most severe ones. In this thesis, I have therefore applied the plasmonic plastic hybrid material concept to tackle these challenges. In summary, I have (i) developed hysteresis-free plasmonic hydrogen sensors based on PdAu, PdCu and PdAuCu alloy nanoparticles; (ii) demonstrated ultrafast sensor response and stable sensor operation in chemically challenging environments using polymer coatings; (iii) introduced bulk-processed and 3D printed plasmonic plastic hydrogen sensors with fast response and high resistance against poisoning and deactivation

On-chip biosensing platforms based on gold and silicon optical nano-resonators

Point-of-care (POC) devices are compact, mobile and fast detection platforms expected to advance early diagnosis, treatment monitoring and personalized healthcare, and revolutionize today’s healthcare system, especially in remote areas. The need for POC devices strongly drives the development of novel biosensor technology. Building a small, fast, simple, and sensitive platform for biomolecule detection is a challenge that relies on the integration of multiple fields of expertise and engineering. Optical nanoresonators have shown great promise as label-free biosensors because of direct light coupling and sub-wavelength sensing modes. Metallic nanoresonators with localized surface plasmon resonances (LSPR) are already well studied and were proven a solid alternative to the commercialized surface plasmon resonance (SPR) sensors. More recently, dielectric nanoresonators have also gained traction due to the reduced losses and the ability to manipulate both the electric and magnetic components of the incident light. In this thesis, we advance the field of biosensing and use optical nanoresonators as operative platforms relevant for disease diagnosis and treatment monitoring. By combining different optimized optical nanoresonators, both metallic and dielectric, with state-of-the-art microfluidics and surface chemistry, we have developed and tested several detection platforms. We first focused on developing a microfluidic lab-on-chip device for multiplexed biosensing utilizing the LSPR of gold nanoresonator arrays. By simultaneously tracking the extinction of 32 sensor arrays, we demonstrated multiplexed quantitative detection of four breast cancer markers in human serum. We showed that with well-optimized immunoassays, a low limit of detection (LOD) can be reached, paving the way towards clinically-relevant POC devices. Additionally, we implemented silicon nanoresonators supporting Mie resonances into functional and clinically-relevant applications. By integrating several arrays of Si nanoresonators with state-of-the-art microfluidics, we demonstrated their ability to detect cancer markers in human serum with high sensitivity and high specificity. Furthermore, we showed that the fabrication of Si nanoresonator array using low cost and scalable projection lithography leads to sufficiently low limits of detection, while enabling cheaper and faster sensor production for future POC applications. We also investigated the respective role of electric and magnetic dipole resonances and showed that they are associated with two different transduction mechanisms: resonance redshift and extinction decrease. Our work advances the development of future point-of-care sensing platforms for fast and low cost health monitoring at the molecular scale.La instrumentación Point-of-care (POC) es compacta, móvil y permite una detección rápida, razón por la que se prevé que sean de gran ayuda en áreas como el diagnostico precoz, la monitorización de tratamientos y la medicina personalizada, revolucionando los modelos sanitarios, especialmente en las zonas de difícil acceso y con menos recursos. La necesidad de este tipo de dispositivos impulsa el desarrollo de novedosas tecnologías en el campo de los bio-sensores. Diseñar equipos para la detección de bio-moléculas que sean rápidos, pequeños y sencillos es un reto que requiere la integración de múltiples campos de la ciencia y la ingeniería. Los nano-resonadores ópticos muestran un gran potencial como bio-sensores sin necesidad de marcaje, gracias a su capacidad de acoplase directamente con la luz en modos menores que la longitud de onda. Los nano-resonadores metálicos basados en resonancias plasmónicas superficiales localizadas (LSPR) han sido estudiados y han demostrado ser una firme alternativa a los ya comerciales basados en resonancias plasmónicas superficiales (SPR). Los nano-resonadores dieléctricos han sido recientemente objeto de atención debido a sus bajas perdidas y la capacidad de manipular los componentes eléctricos y magnéticos de la luz. En esta tesis presentamos avances en el campo de la bio-detección y en el uso de los nano-resonadores ópticos como potenciales herramientas para la detección de enfermedades y monitorización de los tratamientos. Hemos desarrollado y evaluado distintas plataformas de detección combinando los nano-resonadores ópticos, tanto metálicos como dieléctricos, con las más avanzadas técnicas de microfluídica y química de superficies. En primer lugar, nos centramos en el desarrollo de un dispositivo microfluídico basado en sensores LSPR de oro que permite multiplexar 32 canales. Los 32 sensores se monitorizan en tiempo real para demostrar la cuantificación de 4 marcadores de cáncer de mama en suero sanguíneo humano. Demostramos que mediante la optimización de los ensayos se pueden alcanzar bajos límites de detección (LOD), lo que allana el camino hacia dispositivos POC de uso clínico. Por otro lado, hemos utilizado los nano-resonadores de silicio integrados con la microfluídica para también detectar marcadores de cáncer en suero. Estos sensores, cuyo principio de funcionamiento se basa en resonancias de MIE, han demostrado ser una alternativa razonable a los sensores de oro. Además, demostramos que un proceso de fabricación de nano-resonadores de silicio rápido, escalable y de bajo coste da lugar a límites de detección suficientes para la producción de futuras POC. También realizamos un minucioso estudio del rol de las resonancias eléctricas y magnéticas en dichos sensores y su relación con el desplazamiento y el cambio magnitud de la resonancia del sensor global. Nuestro trabajo es un avance en el desarrollo de futuros instrumentos POC rápidos y baratos en el ámbito de la salud a escala molecular.Postprint (published version

On-chip biosensing platforms based on gold and silicon optical nano-resonators

Point-of-care (POC) devices are compact, mobile and fast detection platforms expected to advance early diagnosis, treatment monitoring and personalized healthcare, and revolutionize today’s healthcare system, especially in remote areas. The need for POC devices strongly drives the development of novel biosensor technology. Building a small, fast, simple, and sensitive platform for biomolecule detection is a challenge that relies on the integration of multiple fields of expertise and engineering. Optical nanoresonators have shown great promise as label-free biosensors because of direct light coupling and sub-wavelength sensing modes. Metallic nanoresonators with localized surface plasmon resonances (LSPR) are already well studied and were proven a solid alternative to the commercialized surface plasmon resonance (SPR) sensors. More recently, dielectric nanoresonators have also gained traction due to the reduced losses and the ability to manipulate both the electric and magnetic components of the incident light. In this thesis, we advance the field of biosensing and use optical nanoresonators as operative platforms relevant for disease diagnosis and treatment monitoring. By combining different optimized optical nanoresonators, both metallic and dielectric, with state-of-the-art microfluidics and surface chemistry, we have developed and tested several detection platforms. We first focused on developing a microfluidic lab-on-chip device for multiplexed biosensing utilizing the LSPR of gold nanoresonator arrays. By simultaneously tracking the extinction of 32 sensor arrays, we demonstrated multiplexed quantitative detection of four breast cancer markers in human serum. We showed that with well-optimized immunoassays, a low limit of detection (LOD) can be reached, paving the way towards clinically-relevant POC devices. Additionally, we implemented silicon nanoresonators supporting Mie resonances into functional and clinically-relevant applications. By integrating several arrays of Si nanoresonators with state-of-the-art microfluidics, we demonstrated their ability to detect cancer markers in human serum with high sensitivity and high specificity. Furthermore, we showed that the fabrication of Si nanoresonator array using low cost and scalable projection lithography leads to sufficiently low limits of detection, while enabling cheaper and faster sensor production for future POC applications. We also investigated the respective role of electric and magnetic dipole resonances and showed that they are associated with two different transduction mechanisms: resonance redshift and extinction decrease. Our work advances the development of future point-of-care sensing platforms for fast and low cost health monitoring at the molecular scale.La instrumentación Point-of-care (POC) es compacta, móvil y permite una detección rápida, razón por la que se prevé que sean de gran ayuda en áreas como el diagnostico precoz, la monitorización de tratamientos y la medicina personalizada, revolucionando los modelos sanitarios, especialmente en las zonas de difícil acceso y con menos recursos. La necesidad de este tipo de dispositivos impulsa el desarrollo de novedosas tecnologías en el campo de los bio-sensores. Diseñar equipos para la detección de bio-moléculas que sean rápidos, pequeños y sencillos es un reto que requiere la integración de múltiples campos de la ciencia y la ingeniería. Los nano-resonadores ópticos muestran un gran potencial como bio-sensores sin necesidad de marcaje, gracias a su capacidad de acoplase directamente con la luz en modos menores que la longitud de onda. Los nano-resonadores metálicos basados en resonancias plasmónicas superficiales localizadas (LSPR) han sido estudiados y han demostrado ser una firme alternativa a los ya comerciales basados en resonancias plasmónicas superficiales (SPR). Los nano-resonadores dieléctricos han sido recientemente objeto de atención debido a sus bajas perdidas y la capacidad de manipular los componentes eléctricos y magnéticos de la luz. En esta tesis presentamos avances en el campo de la bio-detección y en el uso de los nano-resonadores ópticos como potenciales herramientas para la detección de enfermedades y monitorización de los tratamientos. Hemos desarrollado y evaluado distintas plataformas de detección combinando los nano-resonadores ópticos, tanto metálicos como dieléctricos, con las más avanzadas técnicas de microfluídica y química de superficies. En primer lugar, nos centramos en el desarrollo de un dispositivo microfluídico basado en sensores LSPR de oro que permite multiplexar 32 canales. Los 32 sensores se monitorizan en tiempo real para demostrar la cuantificación de 4 marcadores de cáncer de mama en suero sanguíneo humano. Demostramos que mediante la optimización de los ensayos se pueden alcanzar bajos límites de detección (LOD), lo que allana el camino hacia dispositivos POC de uso clínico. Por otro lado, hemos utilizado los nano-resonadores de silicio integrados con la microfluídica para también detectar marcadores de cáncer en suero. Estos sensores, cuyo principio de funcionamiento se basa en resonancias de MIE, han demostrado ser una alternativa razonable a los sensores de oro. Además, demostramos que un proceso de fabricación de nano-resonadores de silicio rápido, escalable y de bajo coste da lugar a límites de detección suficientes para la producción de futuras POC. También realizamos un minucioso estudio del rol de las resonancias eléctricas y magnéticas en dichos sensores y su relación con el desplazamiento y el cambio magnitud de la resonancia del sensor global. Nuestro trabajo es un avance en el desarrollo de futuros instrumentos POC rápidos y baratos en el ámbito de la salud a escala molecular

Development of Optical Biosensors Based on Metal Nanostructures for Pollution (Mycotoxins) Detection

This work aims to develop optical biosensors for detection of the bio-toxins, particularly mycotoxins. The main detection technology chosen is a combination of a localized surface plasmon resonance (LSPR) transducer with direct immunoassay with specific bio-receptors antibodies or aptamers immobilized on the gold surface. The LSPR platform is based on gold nano-islands produced by thermal annealing of thin gold films deposited on glass. Thermal annealing was substituted with much quicker and more efficient microwave annealing in later stages of the project. The gold nano-structures produced were analyzed with scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), optical absorption spectroscopy, and spectroscopic ellipsometry. The method of total internal reflection ellipsometry (TIRE) was chosen for LSPR bio-sensing because of its superior sensitivity as compared to conventional UV-vis absorption spectroscopy. The TIRE spectroscopic measurements were performed using the experimental set-up developed on the basis of J.A. Woollam M2000 spectroscopic instrument. The sensitivity of LSPR measurements is however limited by a finite evanescent field decay length in gold nano-islands which is typically in the range of tens of nanometres. In order to achieve the best results, the bio-receptors must be small and placed as close to the gold surface as possible. In our case the problem was solved using either halved antibodies or aptamers immobilized covalently on the surface of gold. A series of bio-sensing experiments to detect mycotoxins, i. e. aflatoxin B1, M1, zearalenone, and ochratoxin A, went successfully and resulted in the detection of the above mycotoxins in concentrations down to 0.01ng/mL. In this work we attempted, for the first time, the TIRE detection of Aflatoxin B1, M1 and ochratoxin A (OTA) in an assay with a specific aptamer. We compared the results obtained for the detection of mycotoxins using bio-receptors of different dimensions: large-size whole antibodies electrostatically immobilized on the surface of gold nano-islands, and small-size split antibodies or specific aptamers immobilised via thiol (SH) groups. For small-size receptors, the low detection limit (LDL) was 0.01ng/ml which is one order of magnitude lower than for whole antibodies. The results obtained demonstrate the advantages of using small bio-receptors in LSPR bio-sensing. The minimal detected concentration OTA was 0.01ng/ml, which is a remarkable result for direct aptamer assay format. The mycotoxin/aptamer binding kinetics were analysed using dynamic TIRE measurements and yeilded an association constant KA in the range of 107 Mol-1 which confirmed the high specificity of aptamer. An attempt to make gold nanostructures for SERS biosensing using nanosphere lithography was successful