Intégration monolithique de multiples membranes de silicium poreux pour laboratoires sur puce

La principale cause de mortalité dans le monde est due à des maladies traitables non diagnostiquées. La raison sous-jacente est le coût et la complexité de la plupart des processus de diagnostic, car ils sont souvent réalisés dans des centres médicaux et nécessitent des équipements coûteux et compliqués. Pour résoudre ce problème, le développement d'une technologie au point de service utilisant des laboratoires sur puce miniaturisés et peu coûteux revêt une grande importance. L'analyse d'un échantillon comprend deux étapes principales : la préparation de l'échantillon (purification et pré concentration de l'échantillon) et son analyse (bio détection). Différentes technologies ont été développées avec succès pour implémenter ces étapes sur puce, cependant elles sont généralement intégrées de manière hybride, où le biocapteur et le module de préparation de l'échantillon sont réalisés séparément puis combinés, ce qui augmente la complexité du dispositif et éventuellement son coût final. L'objectif de ce travail est d'offrir une réponse technologique générique et unique pour la préparation et la détection d'échantillons sur puce au moyen d'éléments en silicium poreux, sous la forme de membranes latérales en silicium poreux et de couches verticales standard en silicium poreux fabriquées de manière monolithique sur une seule puce micro fluidique plane. Le silicium poreux est un matériau nanostructuré aux caractéristiques électriques et optiques intéressantes qui a déjà été utilisé pour la bio détection par interférométrie basée sur la réflectance lorsqu'il est correctement fonctionnalisé et pour la filtration basée sur la taille et la charge. En outre, c'est un bon candidat pour la concentration d'échantillons par polarisation de la concentration ionique, en raison de sa propriété de sélectivité ionique. Cependant, il faut être capable de fabriquer de multiples éléments en silicium poreux avec des morphologies spécifiques (taille des pores et porosité) sur la même puce, ce qui n'a pas encore été réalisé, afin d'utiliser le silicium poreux comme une brique technologique générique pour diverses fonctions. Le silicium poreux est généralement fabriqué par anodisation électrochimique et l'état de dopage du silicium est l'un des paramètres qui contrôle la morphologie de la couche poreuse. Nous avons donc développé un procédé de fabrication basé sur l'implantation ionique sélective de substrats SOI afin d'obtenir de nombreux éléments poreux de caractéristiques distinctes en utilisant une seule étape d'anodisation. Nous avons réussi à fabriquer des membranes latérales poreuses en silicium pontant des micro canaux planaires avec une augmentation de deux fois la taille des pores entre les régions non implantées et implantées sur une seule puce (de ~25 à ~50 nm), tandis que la porosité variait de ~80 à ~90%. En gravant la couche d'oxyde enterrée, nous avons également formé des couches de silicium poreuses verticales, avec une taille de pores de ~35 nm et une porosité de ~65%, au fond des micro canaux sur le même échantillon. En utilisant les procédés de fabrication développés, nous avons conçu et fabriqué un laboratoire sur puce monolithique intégrant des étapes de pré concentration et de filtration de l'échantillon, avec un potentiel de réalisation de bio détection par interférométrie optique.The leading cause of mortality worldwide is due to undiagnosed treatable diseases. The underlying reason is the cost and complexity of most diagnostic processes, as they are often carried out in medical centers and require expensive and complicated equipment. To tackle this issue, the development of point-of-care technology using miniaturized and low-cost lab-on-a-chip is of great importance. The analysis of a sample includes two main steps: sample preparation (sample purification and preconcentration) and sample analysis (biosensing). Different technologies have been successfully developed to implement these steps on chip, however they are usually integrated in a hybrid fashion, where the biosensor and the sample preparation module are realized separately and then combined, which increases the device complexity and possibly its final cost. The aim of this work is to offer a generic and single technological response for on chip sample preparation and sensing by means of porous silicon elements, in the form of lateral porous silicon membranes and standard vertical porous silicon layers monolithically fabricated onto a single planar microfluidic chip. Porous silicon is a nanostructured material with interesting electrical and optical characteristics that has already been used for biosensing via reflectance-based interferometry when properly functionalized and for size/charge-based filtration. Besides, it is a strong candidate for sample concentration using ion concentration polarization due to its ion-selectivity property. However, one must be able to fabricate multiple porous silicon elements with specific morphologies (pore size and porosity) on the same chip, which has not been achieved yet, in order to use porous silicon as a generic technological brick for various functions. Porous silicon is usually fabricated through electrochemical anodization and the doping condition of silicon is one of the parameters that controls the porous layer morphology. We have thus developed a fabrication process based on the selective ion implantation of SOI substrates in order to achieve numerous porous elements of distinct characteristics using a single anodization step. We have successfully fabricated lateral porous silicon membranes bridging planar microchannels with twofold increase in pore size from non-implanted to implanted regions onto a single chip (from ~25 to ~50 nm), while the porosity varied from ~80 to ~90%. By etching the buried oxide layer, we have also formed vertical porous silicon layers, with ~35 nm pore size and ~65% porosity, at the bottom of the microchannels on the same sample. Using the developed fabrication processes, we have designed and fabricated a monolithic lab-on-a-chip integrating sample preconcentration and filtration stages, with a potential to achieve biosensing through optical interferometry

Recital de formatura online: compartilhando saberes musicais e tecnológicos durante a pandemia / Online Graduation Recital: sharing musical and technological knowledge during the pandemic

Esse artigo relata o processo de construção e execução de um Recital de Formatura Online durante a pandemia e todos os enfrentamentos para a aceitação dessa nova modalidade, no meio acadêmico. O texto conjuga as experiências do aluno e do professor e descreve o desenvolvimento de formas alternativas de comunicação e de compartilhamento de saberes musicais e tecnológicos. Novas interações surgiram entre professor e aluno, entre performer e público, por meio de softwares e plataformas online. Nesse período de isolamento social, a necessidade de utilização de recursos tecnológicos forçou um aprendizado fora do círculo acadêmico e sem tutoria presencial, além de estimular a capacitação de docentes e discentes em áreas anteriormente consideradas não prioritárias. Parte do conhecimento adquirido nessa empreitada foi fruto da interação do aluno com outros alunos, de forma colaborativa. O artigo descreve os desafios da gravação de áudio e vídeo de forma remota e a apresentação de um recital, no qual público e performer interagem de forma não presencial, possibilitando o aumento do alcance de público

COMPOSICIÓN FLORÍSTICA DE QUINTAIS AGROFLORESTAIS EN LA VILA CUERA, BRAGANZA, PARÁ

RESUMO: Os quintais agroflorestais caracterizam-se como um sistema tradicional de utilização da terra, usados por famílias residentes em zonas rurais, periurbanas e urbanas e possuem relevância quando se trata da conservação da biodiversidade. Este trabalhou objetivou caracterizar a composição florística de quintais agroflorestais na Vila Cuera, município de Bragança, estado do Pará. Para realização deste trabalho, foram selecionados aleatoriamente, quatro quintais agroflorestais, na Vila de Cuera, zona rural, no município de Bragança, Pará, onde foi aplicado um questionário semiestruturado para as famílias. Mediu-se o diâmetro a altura do peito (DAP), o tamanho dos quatros quintais, o que totalizou uma área média de 1.819,28 m² e, estimou-se a altura das espécies existentes nas áreas. Posteriormente, a comunidade foi dividida em estrato superior, médio e inferior, sendo calculados os parâmetros fitossociológicos de frequência relativa, índice de diversidade de Shannon-Wiener (H’) e equabilidade de Pielou (J’). Foram registrados 217 indivíduos, que podem ser direcionados tanto para a comercialização quanto para o consumo familiar, bem como para o uso na medicina caseira e no âmbito ornamental. Ademais, muitos indivíduos estão presentes no estrato inferior, o que caracteriza uma comunidade com plantas jovens, sendo o açaizeiro e o coqueiro encontrados em todos os estratos e com alta frequência. No mais, as áreas são compostas por um aglomerado bastante diverso de espécies arbóreas, herbáceas e arbustivas. Desta forma, os quintais agroflorestais são manejados de maneira tradicional pelos mantedores, grande parte das espécies está voltada para o consumo e posterior comercialização e, uma elevada diversidade de espécies.PALAVRAS-CHAVE: Amazônia, Agroecossistemas, Segurança alimentar.ABSTRACT: The agroforestry yards are characterized as a traditional land use system, by means of residents in rural, peri-urban and urban areas and services related to the acquisition of biodiversity conservation. This work is a project for the production of agroforestry farms in Vila Cuera, Bragança municipality, state of Pará. For this work, four agroforestry farms were randomly selected in Vila de Cuera, a rural area, in the municipality of Bragança, Pará, where a semi-structured questionnaire for families was published. The diameter at breast height (DBH), the size of the four quintals, was measured, which totaled an average area of 1,819.28 m² and the height of the species in the areas was estimated. Subsequently, the community was divided into upper, middle and lower strata, and the relative frequency phytosociological parameters, Shannon-Wiener diversity index (H ') and Pielou equability (J') were calculated. A total of 217 individuals were enrolled, which can be targeted both for marketing and family consumption, as well as for use in home medicine and ornamental medicine. In addition, many individuals are present in the lower stratum, which characterizes a community with young plants, with açai and coconut trees found in all strata and with high frequency. In addition, the areas are composed of a very diverse cluster of arboreal, herbaceous and shrub species. In this way, agroforestry yards are managed in a traditional way by the keepers, most of the species are focused on consumption and subsequent commercialization, and a high diversity of species.KEYWORDS: Amazon, Agroecosystems, Food safety.RESUMEN: Los quintos agroforestales se caracterizan como un sistema tradicional de utilización de la tierra, utilizados por familias residentes en zonas rurales, periurbanas y urbanas y tienen relevancia cuando se trata de la conservación de la biodiversidad. En el presente trabajo se analizaron los resultados obtenidos en el análisis de los resultados obtenidos en el estudio de los resultados obtenidos en el estudio, donde se aplicó un cuestionario semiestructurado para las familias. Se midió el diámetro a la altura del pecho (DAP), el tamaño de los quatros quintos, lo que totalizó un área promedio de 1.819,28 m² y, se estimó la altura de las especies existentes en las áreas. En la mayoría de los casos, la comunidad se dividió en estrato superior, medio e inferior, calculando los parámetros fitosociológicos de frecuencia relativa, índice de diversidad de Shannon-Wiener (H ') y la equidad de Pielou (J'). Se registraron 217 individuos, que pueden ser dirigidos tanto para la comercialización como para el consumo familiar, así como para el uso en la medicina casera y en el ámbito ornamental. Además, muchos individuos están presentes en el estrato inferior, lo que caracteriza a una comunidad con plantas jóvenes, siendo el açaiceiro y el cocotero encontrados en todos los estratos y con alta frecuencia. En el más, las áreas están compuestas por un aglomerado bastante diverso de especies arbóreas, herbáceas y arbustivas. De esta forma, los quintos agroforestales son manejados de manera tradicional por los mantedores, gran parte de las especies está orientada hacia el consumo y posterior comercialización y, una elevada diversidad de especies. PALABRAS CLAVE: Amazonia, Agroecosistemas, Seguridad alimentaria

Challenges and implementation of the “Programa Mais Médicos Campineiro”

The aim of this study is to describe the experience of implementing the Programa Mais Médicos Campineiro (PMMC) in Campinas city, State of São Paulo, Brazil, from April 2019 to April 2020, as the result of a health policy that suited the municipality’s needs to the doctors’ training program in Family and Community Medicine. For such purpose, information from meeting registries was assembled from several sources, to recover the series of actions taken to achieve an effective proposal. The situation of primary health care in the municipality until 2019 was analyzed in detail, which revealed difficulties in fixating doctors in Health Units. As a solution, the institution of a medical residency program was chosen. To preserve the doctor’s maintenance in the PMMC, he was admitted to the Family Health Strategy. Funding was allocated to guarantee sufficient compensation to attract and engage professionals to the proposal. The selection process of medical residents and preceptors was widely discussed and a pedagogical program was created and the program’s management was established. An increase in the number of vacancies offered was noted, demonstrating that, through public policy aimed at training Family and Community Physicians, it is possible to change the scenario of idleness as well as the high turnover of vacancies in medical residency programs in Campinas.O objetivo deste trabalho é descrever a experiência da implementação do Programa Mais Médicos Campineiro (PMMC) na cidade de Campinas, Estado de São Paulo, no período de abril de 2019 a abril de 2020, como resultado de política de saúde que adequou as necessidades do município à formação de médicos especialistas em Medicina da Família e Comunidade. Para tal, foram compilados registros de reuniões realizadas entre integrantes da Secretaria Municipal de Saúde e instituições de ensino superior do município e recuperada a trajetória percorrida pelos diversos atores envolvidos. A situação da atenção básica de saúde no município até 2019 foi analisada com detalhes, o que revelou dificuldades em fixar o médico nas Unidades de Saúde. Como solução optou-se pela instituição de programa de residência médica. Para preservar a manutenção do médico no programa, garantiu-se a sua vinculação à Estratégia de Saúde da Família, foram estabelecidas parcerias com instituições de saúde e foi planejado o financiamento que garantiu remuneração suficiente para atrair e manter profissionais à proposta. O processo seletivo de médicos residentes e preceptores foi amplamente discutido. Foi criado um programa pedagógico e estabelecida a gestão do programa. Foi verificado incremento da ocupação de vagas oferecida, demonstrando-se que por meio de política pública direcionada à formação de Médico da Família e Comunidade é possível alterar o panorama de ociosidade assim como a alta rotatividade de vagas em programas de residência médica em Campinas

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

Monolithic Integration of Multiple Porous Silicon Membranes for Lab-on-a-chip Applications

La principale cause de mortalité dans le monde est due à des maladies traitables non diagnostiquées. La raison sous-jacente est le coût et la complexité de la plupart des processus de diagnostic, car ils sont souvent réalisés dans des centres médicaux et nécessitent des équipements coûteux et compliqués. Pour résoudre ce problème, le développement d'une technologie au point de service utilisant des laboratoires sur puce miniaturisés et peu coûteux revêt une grande importance. L'analyse d'un échantillon comprend deux étapes principales : la préparation de l'échantillon (purification et pré concentration de l'échantillon) et son analyse (bio détection). Différentes technologies ont été développées avec succès pour implémenter ces étapes sur puce, cependant elles sont généralement intégrées de manière hybride, où le biocapteur et le module de préparation de l'échantillon sont réalisés séparément puis combinés, ce qui augmente la complexité du dispositif et éventuellement son coût final. L'objectif de ce travail est d'offrir une réponse technologique générique et unique pour la préparation et la détection d'échantillons sur puce au moyen d'éléments en silicium poreux, sous la forme de membranes latérales en silicium poreux et de couches verticales standard en silicium poreux fabriquées de manière monolithique sur une seule puce micro fluidique plane. Le silicium poreux est un matériau nanostructuré aux caractéristiques électriques et optiques intéressantes qui a déjà été utilisé pour la bio détection par interférométrie basée sur la réflectance lorsqu'il est correctement fonctionnalisé et pour la filtration basée sur la taille et la charge. En outre, c'est un bon candidat pour la concentration d'échantillons par polarisation de la concentration ionique, en raison de sa propriété de sélectivité ionique. Cependant, il faut être capable de fabriquer de multiples éléments en silicium poreux avec des morphologies spécifiques (taille des pores et porosité) sur la même puce, ce qui n'a pas encore été réalisé, afin d'utiliser le silicium poreux comme une brique technologique générique pour diverses fonctions. Le silicium poreux est généralement fabriqué par anodisation électrochimique et l'état de dopage du silicium est l'un des paramètres qui contrôle la morphologie de la couche poreuse. Nous avons donc développé un procédé de fabrication basé sur l'implantation ionique sélective de substrats SOI afin d'obtenir de nombreux éléments poreux de caractéristiques distinctes en utilisant une seule étape d'anodisation. Nous avons réussi à fabriquer des membranes latérales poreuses en silicium pontant des micro canaux planaires avec une augmentation de deux fois la taille des pores entre les régions non implantées et implantées sur une seule puce (de ~25 à ~50 nm), tandis que la porosité variait de ~80 à ~90%. En gravant la couche d'oxyde enterrée, nous avons également formé des couches de silicium poreuses verticales, avec une taille de pores de ~35 nm et une porosité de ~65%, au fond des micro canaux sur le même échantillon. En utilisant les procédés de fabrication développés, nous avons conçu et fabriqué un laboratoire sur puce monolithique intégrant des étapes de pré concentration et de filtration de l'échantillon, avec un potentiel de réalisation de bio détection par interférométrie optique.The leading cause of mortality worldwide is due to undiagnosed treatable diseases. The underlying reason is the cost and complexity of most diagnostic processes, as they are often carried out in medical centers and require expensive and complicated equipment. To tackle this issue, the development of point-of-care technology using miniaturized and low-cost lab-on-a-chip is of great importance. The analysis of a sample includes two main steps: sample preparation (sample purification and preconcentration) and sample analysis (biosensing). Different technologies have been successfully developed to implement these steps on chip, however they are usually integrated in a hybrid fashion, where the biosensor and the sample preparation module are realized separately and then combined, which increases the device complexity and possibly its final cost. The aim of this work is to offer a generic and single technological response for on chip sample preparation and sensing by means of porous silicon elements, in the form of lateral porous silicon membranes and standard vertical porous silicon layers monolithically fabricated onto a single planar microfluidic chip. Porous silicon is a nanostructured material with interesting electrical and optical characteristics that has already been used for biosensing via reflectance-based interferometry when properly functionalized and for size/charge-based filtration. Besides, it is a strong candidate for sample concentration using ion concentration polarization due to its ion-selectivity property. However, one must be able to fabricate multiple porous silicon elements with specific morphologies (pore size and porosity) on the same chip, which has not been achieved yet, in order to use porous silicon as a generic technological brick for various functions. Porous silicon is usually fabricated through electrochemical anodization and the doping condition of silicon is one of the parameters that controls the porous layer morphology. We have thus developed a fabrication process based on the selective ion implantation of SOI substrates in order to achieve numerous porous elements of distinct characteristics using a single anodization step. We have successfully fabricated lateral porous silicon membranes bridging planar microchannels with twofold increase in pore size from non-implanted to implanted regions onto a single chip (from ~25 to ~50 nm), while the porosity varied from ~80 to ~90%. By etching the buried oxide layer, we have also formed vertical porous silicon layers, with ~35 nm pore size and ~65% porosity, at the bottom of the microchannels on the same sample. Using the developed fabrication processes, we have designed and fabricated a monolithic lab-on-a-chip integrating sample preconcentration and filtration stages, with a potential to achieve biosensing through optical interferometry

Intégration monolithique de multiples membranes de silicium poreux pour laboratoires sur puce

National audienceThe leading cause of mortality worldwide is due to undiagnosed treatable diseases. The underlying reason is the cost and complexity of most diagnostic processes, as they are often carried out in medical centers and require expensive and complicated equipment. To tackle this issue, the development of point-of-care technology using miniaturized and low-cost lab-on-a-chip is of great importance. The analysis of a sample includes two main steps: sample preparation (sample purification and preconcentration) and sample analysis (biosensing). Different technologies have been successfully developed to implement these steps on chip, however they are usually integrated in a hybrid fashion, where the biosensor and the sample preparation module are realized separately and then combined, which increases the device complexity and possibly its final cost. The aim of this work is to offer a generic and single technological response for on chip sample preparation and sensing by means of porous silicon elements, in the form of lateral porous silicon membranes and standard vertical porous silicon layers monolithically fabricated onto a single planar microfluidic chip. Porous silicon is a nanostructured material with interesting electrical and optical characteristics that has already been used for biosensing via reflectance-based interferometry when properly functionalized and for size/charge-based filtration. Besides, it is a strong candidate for sample concentration using ion concentration polarization due to its ion-selectivity property. However, one must be able to fabricate multiple porous silicon elements with specific morphologies (pore size and porosity) on the same chip, which has not been achieved yet, in order to use porous silicon as a generic technological brick for various functions. Porous silicon is usually fabricated through electrochemical anodization and the doping condition of silicon is one of the parameters that controls the porous layer morphology. We have thus developed a fabrication process based on the selective ion implantation of SOI substrates in order to achieve numerous porous elements of distinct characteristics using a single anodization step. We have successfully fabricated lateral porous silicon membranes bridging planar microchannels with twofold increase in pore size from non-implanted to implanted regions onto a single chip (from ~25 to ~50 nm), while the porosity varied from ~80 to ~90%. By etching the buried oxide layer, we have also formed vertical porous silicon layers, with ~35 nm pore size and ~65% porosity, at the bottom of the microchannels on the same sample. Using the developed fabrication processes, we have designed and fabricated a monolithic lab-on-a-chip integrating sample preconcentration and filtration stages, with a potential to achieve biosensing through optical interferometry.La principale cause de mortalité dans le monde est due à des maladies traitables non diagnostiquées. La raison sous-jacente est le coût et la complexité de la plupart des processus de diagnostic, car ils sont souvent réalisés dans des centres médicaux et nécessitent des équipements coûteux et compliqués. Pour résoudre ce problème, le développement d'une technologie au point de service utilisant des laboratoires sur puce miniaturisés et peu coûteux revêt une grande importance. L'analyse d'un échantillon comprend deux étapes principales : la préparation de l'échantillon (purification et pré concentration de l'échantillon) et son analyse (bio détection). Différentes technologies ont été développées avec succès pour implémenter ces étapes sur puce, cependant elles sont généralement intégrées de manière hybride, où le biocapteur et le module de préparation de l'échantillon sont réalisés séparément puis combinés, ce qui augmente la complexité du dispositif et éventuellement son coût final. L'objectif de ce travail est d'offrir une réponse technologique générique et unique pour la préparation et la détection d'échantillons sur puce au moyen d'éléments en silicium poreux, sous la forme de membranes latérales en silicium poreux et de couches verticales standard en silicium poreux fabriquées de manière monolithique sur une seule puce micro fluidique plane. Le silicium poreux est un matériau nanostructuré aux caractéristiques électriques et optiques intéressantes qui a déjà été utilisé pour la bio détection par interférométrie basée sur la réflectance lorsqu'il est correctement fonctionnalisé et pour la filtration basée sur la taille et la charge. En outre, c'est un bon candidat pour la concentration d'échantillons par polarisation de la concentration ionique, en raison de sa propriété de sélectivité ionique. Cependant, il faut être capable de fabriquer de multiples éléments en silicium poreux avec des morphologies spécifiques (taille des pores et porosité) sur la même puce, ce qui n'a pas encore été réalisé, afin d'utiliser le silicium poreux comme une brique technologique générique pour diverses fonctions. Le silicium poreux est généralement fabriqué par anodisation électrochimique et l'état de dopage du silicium est l'un des paramètres qui contrôle la morphologie de la couche poreuse. Nous avons donc développé un procédé de fabrication basé sur l'implantation ionique sélective de substrats SOI afin d'obtenir de nombreux éléments poreux de caractéristiques distinctes en utilisant une seule étape d'anodisation. Nous avons réussi à fabriquer des membranes latérales poreuses en silicium pontant des micro canaux planaires avec une augmentation de deux fois la taille des pores entre les régions non implantées et implantées sur une seule puce (de ~25 à ~50 nm), tandis que la porosité variait de ~80 à ~90%. En gravant la couche d'oxyde enterrée, nous avons également formé des couches de silicium poreuses verticales, avec une taille de pores de ~35 nm et une porosité de ~65%, au fond des micro canaux sur le même échantillon. En utilisant les procédés de fabrication développés, nous avons conçu et fabriqué un laboratoire sur puce monolithique intégrant des étapes de pré concentration et de filtration de l'échantillon, avec un potentiel de réalisation de bio détection par interférométrie optique

Localized protection of high aspect ratio trenches based on the anisotropy manipulation of plasma-polymerized fluoropolymer coating

International audienc

Optical interferometry on lateral porous silicon

International audienceWe demonstrate the transducing ability of lateral porous silicon membranes (LPSi) using optical interferometry. To this aim, we use a Fourier Transform Infra-Red spectrometer (FTIR) coupled to a microscope stage equipped with an appropriate objective in order to overcome the difficulty to obtain interference signal from the LPSi membrane with small dimensions. We have recorded reflectance spectra upon filling the membrane with various solvents and the observed shifts of Fabry-Pérot fringe patterns indicate that the we are able to differentiate between solvents, thus providing a proof-of-concept of the LPSi interferometric transducer