Dans ce travail de thèse, le microscope à force atomique (AFM) a été utilisé comme outil de manipulation de haute précision pour construire des nanostructures plasmoniques avec des géométries définies et un réglage précis de la distance interparticulaire et également comme technique de spectroscopie d'absorption. Différentes études concernant les phénomènes pertinents pour la manipulation des nanoparticules et émergeant à l'interface substrat-nanoparticules, ont été réalisées. Des expériences de frottement menées sur diverses surfaces d'oxydes ont révélé un nouveau mécanisme de frottement à l’échelle nanométrique, expliqué par un modèle de potentiel d'interaction de type Lennard-Jones modifié. Les propriétés de frottement et d'adhésion de CTAB adsorbé sur silice sont également présentées. Des nano-bâtonnets d'or fonctionnalisés par du CTAB ont été manipulés par AFM afin de construire des nanostructures plasmoniques. La dernière partie de la thèse présente les efforts expérimentaux et théoriques pour démontrer la faisabilité de l'utilisation d'un AFM comme une technique de spectroscopie optoélectronique à base de force. / In this thesis work the atomic force microscope (AFM) was employed first as a high precision manipulation tool for building plasmonic nanostructures with defined geometries and precise tuning of interparticle distance and second as an absorption spectroscopy technique. Different studies regarding phenomena emerging at sample nanoparticle interface relevant for nanoparticle manipulation were performed. Friction experiments conducted on various oxide surfaces revealed a novel nanoscale stick slip friction mechanism, explained by a modified Lennard-Jones-like interaction potential model. Frictional and adhesion properties of CTAB adsorbed on silica are also reported. CTAB functionalized gold nanorods were used for building specific plasmonic particulate nanostructures. The final part of the thesis presents experimental and theoretical efforts to demonstrate the feasibility of using an AFM as a force-based optoelectronic spectroscopy technique.

A major difficulty in the fabrication of nanostructure based electronics is the lack of effective processes capable of precisely arranging nanostructures into predefined positions. Top-down approaches introduce increased complexity and a high cost for practical industrial use, while bottom-up approaches are probabilistic in nature and do not provide precise control of nanostructure properties (i.e., number, diameter), which influence device performance. Alternatively, nanomanipulation promises specificity, precision and programmed motion and its automation may facilitate the large-scale fabrication of nanostructure based devices. This study focuses on the development of an automated contact detection algorithm which positions an end-effector in contact with a target surface without the need for additional equipment, devices or sensors. We demonstrate this algorithm as an enabling feature for automated nano-FET biosensor construction with precise control over nanowire parameters thereby reducing device-to-device variability and also potentially allowing us to optimize individual device performance.

A major difficulty in the fabrication of nanostructure based electronics is the lack of effective processes capable of precisely arranging nanostructures into predefined positions. Top-down approaches introduce increased complexity and a high cost for practical industrial use, while bottom-up approaches are probabilistic in nature and do not provide precise control of nanostructure properties (i.e., number, diameter), which influence device performance. Alternatively, nanomanipulation promises specificity, precision and programmed motion and its automation may facilitate the large-scale fabrication of nanostructure based devices. This study focuses on the development of an automated contact detection algorithm which positions an end-effector in contact with a target surface without the need for additional equipment, devices or sensors. We demonstrate this algorithm as an enabling feature for automated nano-FET biosensor construction with precise control over nanowire parameters thereby reducing device-to-device variability and also potentially allowing us to optimize individual device performance.

Avec les dernières avancées en matière de nanotechnologies, il est devenu possible de concevoir, avec une grande efficacité, de nouveaux dispositifs et systèmes nanométriques. Il en résulte la nécessité de dé- velopper des méthodes de pointe fiables pour la nanomanipulation et la nanocaractérisation. La détection directe par l'homme n'étant pas une option envisageable à cette échelle, les tâches sont habituellement effectuées par un opérateur humain expert à l'aide d'un microscope électronique à balayage équipé de dispositifs micro-nanorobotiques. Toutefois, en raison de l'absence de méthodes efficaces, ces tâches sont toujours difficiles et souvent fastidieuses à réaliser. Grâce à ce travail, nous montrons que ce problème peut être résolu efficacement jusqu'à une certaine mesure en utilisant les informations extraites des images. Le travail porte sur l'utilisation des images électroniques pour développer des méthodes automatiques fiables permettant d'effectuer des tâches de nanomanipulation et nanocaractérisation précises et efficaces. En premier lieu, puisque l'imagerie électronique à balayage est affectée par les instabilités de la colonne électronique, des méthodes fonctionnant en temps réel pour surveiller la qualité des images et compenser leur distorsion dynamique ont été développées. Ensuite des lois d'asservissement visuel ont été développ ées pour résoudre deux problèmes. La mise au point automatique utilisant l'asservissement visuel, développée, assure une netteté constante tout au long des processus. Elle a permis d'estimer la profondeur inter-objet, habituellement très dfficile à calculer dans un microscope électronique à balayage. Deux schémas d'asservissement visuel ont été développés pour le problème du nanopositionnement dans un microscope électronique. Ils sont fondés sur l'utilisation directe des intensités des pixels et l'information spectrale, respectivement. Les précisions obtenues par les deux méthodes dans différentes conditions exp érimentales ont été satisfaisantes. Le travail réalisé ouvre la voie à la réalisation d'applications précises et fiables telles que l'analyse topographique, le sondage de nanostructures ou l'extraction d'échantillons pour microscope électronique en transmission.

Orientador: Daniel Mario Ugarte / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-15T02:39:35Z (GMT). No. of bitstreams: 1 Oiko_VitorToshiyukiAbrao_M.pdf: 7596860 bytes, checksum: c9ed7c1eff25bf830795b90b88bdc6fa (MD5) Previous issue date: 2010 / Resumo: O estudo de nano-sistemas tem atraído grande atenção nos últimos anos, principalmente devido às suas possíveis e novas aplicações tecnológicas. Muitos esforços têm sido feitos nessa área, porém há ainda várias questões em aberto com relação à compreensão de nanoestruturas. Um dos principais desafios diz respeito à manipulação e o posicionamento controlado de nano-objetos, juntamente com a quantificação das forças envolvidas e a caracterização das propriedades mecânicas em nanoescala. Muitos avanços foram atingidos com a combinação de técnicas de microscopia de força atômica (AFM). Infelizmente nestes experimentos o sensor de forças também é utilizado para gerar uma imagem da amostra. Assim não é possível visualizar o nano-sistema ao mesmo tempo em que ele é submetido a algum esforço mecânico. Outros experimentos são realizados in situ em microscópios eletrônicos onde são utilizados porta-amostras especiais com sensores de força de microscópios de AFM.Combina-se dessa forma a capacidade de se observar diretamente o nano-sistema com a de aplicar e medir forças em sistemas nanométricos. Nesta dissertação é estudada então uma alternativa para a fabricação de um sensor de forças baseado no uso de diapasões de quartzo (tuning forks). Esse sensor deverá ser utilizado em experimentos de nanomanipulação. Este projeto abordou todos os aspectos necessários à instrumentação, desenho, construção e implementação do sensor. O sensor foi acoplado a um nanomanipulador que opera dentro de um microscópio eletrônico de varredura de alta resolução. Com essa montagem, realizaram-se experimentos preliminares de manipulação e deformação de nanofios semicondutores (InP, de alguns mícrons de comprimento, e de 50-200 nm de diamêtro). As forças foram quantificadas baseando-se nas imagens de microscopia dos fios sendo deformados e utilizando um modelo teórico de deformações elásticas. Esses valores foram correlacionados com as variações das curvas de ressonância do tuning fork, para finalmente obter a calibração do sensor de forças. O sistema permite medir forças com uma sensibilidade de 0:5m N baseando-se somente nas mudanças dos sinais elétricos utilizados para alimentar o diapasão de quartzo / Abstract: The study of nanosystems has attracted great attention in recent years, mainly due to their novel possible technological applications. Many efforts have been made in this area, however there are still several open questions concerning the comprehension of such systems. One of the biggest challenges is the manipulation and the controlled positioning of nano-objects, together with the quantification of the forces involved and the mechanical characterization at the nanoscale. Many advances have been achieved with the combination of atomic force microscopy (AFM) techniques. Unfortunately, in these experiments the force sensor is also applied to generate the sample's images. It doesn't allow the system's visualization simultaneously with the stress application. Other experiments are performed in situ electron microscopes where special sample-holders with AFM cantilevers are used. It combines then the ability of observing the nanosystem directly to the possibility of applying and measuring forces in nanometric scale. In this dissertation it is studied an alternative to the fabrication of a force sensor based on quartz tuning forks. This sensor will be used on nanomanipulation experiments. The project covered all the aspects necessary to the sensor's instrumentation, design, construction and implementation. The sensor was attached to a nanomanipulator that operates inside a high resolution scanning electron microscope. Semiconductor nanowires (InP, a few microns in length and 50-200nm in diameter) were manipulated and deformed with this experimental setup. The force quantification was based on microscopy images of the deformed nanowires and on theoretical model of elastic deformations. The force values were correlated with the variations of tuning fork's resonant curves in order to obtain a calibration curve for the sensor. Sensitivity of 0:5m N were achieved based only on changes on electrical signals fed to the quartz tuning fork / Mestrado / Física da Matéria Condensada / Mestre em Física

Orientadores: Daniel Mario Ugarte, Varlei Rodrigues / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-24T10:25:30Z (GMT). No. of bitstreams: 1 Oiko_VitorToshiyukiAbrao_D.pdf: 44112591 bytes, checksum: 93cb68b7fac3caf690848f58147ff259 (MD5) Previous issue date: 2014 / Resumo: O estudo de nano-sistemas tem atraído grande atenção nos últimos anos, principalmente devido às suas possíveis e novas aplicações tecnológicas. Muitos esforços tem sido feitos nessa área, porém há ainda várias questões em aberto com relação a compreensão de nanoestruturas. Um dos principais desafios diz respeito à manipulação e o posicionamento controlado de nanoobjetos, juntamente com a quantificação das forças envolvidas e a caracterização das propriedades mecânicas em nanoescala. Muitos avanços foram atingidos combinando-se a microscopia eletrônica de varredura (SEM) e a de força atômica (AFM), realizando experimentos in situ que aproveitam a resolução e a formação de imagens do SEM, e a capacidade de medir forças em sistemas nanométricos do AFM. Nesta tese discutimos a quantificação de forças de intensidade < N, aplicadas em experimentos de nanomanipulação in situ de SEM, através do desenvolvimento de um sensor baseado no uso de diapasões de quartzo (tuning fork). Abordamos os aspectos técnicos relevantes à construção do sensor e seu funcionamento, desde o problema de se medir forças da ordem de nN em nano-objetos individuais, até sua aplicação em sistemas dessa dimensão. Pontos fundamentais do desenvolvimento como a definição da sua configuração, da eletrônica de aquisição e da metodologia de calibração e de aplicação são tratados em detalhe. Um processo de calibração baseado na deformação in situ de cantilevers de AFM é utilizado para permitir a quantificação da força. Subsequentemente a medida dos valores é feita exclusivamente através das curvas de ressonância do tuning fork, independendo completamente das imagens de microscopia. Forças no intervalo de 1-100 nN foram medidas, e a aplicação do sensor foi dada no intervalo de 4-40 nN. A precisão obtida na quantificação foi de alguns nN, ?F ?1-4 nN. O sistema foi testado em experimentos de deformação de bundles de nanotubos de carbono in situ em um SEM, nos quais medimos quantitativamente a influência das forças de van der Waals no atrito dinâmico durante o escorregamento entre nanotubos. As forças obtidas nesses experimentos variaram entre 14-35 nN / Abstract: The study of nanosystems has attracted many attention in recent years, mainly due to their novel possible technological applications. Many efforts have been made in this area, however several open questions regarding the comprehension of such structures remain. A major challenge concerns the manipulation and the controlled positioning of nano-objects, together with the quantification of the involved forces and the mechanical characterization at the nanoscale. Many advances have been achieved by combining the scanning electron microscopy (SEM) and the atomic force microscope (AFM), conducting thus in situ experiments that profit from SEM¿s resolution and imaging and from AFM¿s ability to measure forces in nanoscale systems. In this thesis we treat the quantification of forces with intensity < N applied during in situ nanomanipulation experiments performed inside a SEM by developing a force sensor based on quartz tuning forks. Our approach comprises the technical aspects relevant to the sensor¿s assembly and its operation, from the issue of measuring forces of the order of nN on individual nano-objects, to its application on nanosystems. Key points of development such as the sensor¿s design, electronics, calibration and applications are described in details. A calibration process based on the in situ bending AFM cantilevers is carried out to enable the force quantification. Subsequently the force measurement is done exclusively by the TF¿s resonance curve, being completely independent of the microscopy images. Forces in the range of 1-100 nN were measured, and the sensor¿s application was considered between 4 nN and 40 nN. The precison acquired was of a few nN, ?F ?1-4 nN. To test the sensor in situ strain experiments were performed on bundles of carbon nanotubes from which we measured quantitatively the van der Waals¿ influence on the dynamic friction during the sliding of adjacent bundles. The forces acquired were then in the range of 14-35 nN / Doutorado / Física / Doutor em Ciências

Presented in this thesis are two methods that are coupled to the instrumentation for the recovery and analysis of ultra-trace illicit drug residues. The electrostatic dust lifting process is coupled with nanomanipulation-nanospray ionization to retrieve drug particles off of hard surfaces for analysis. For the second method, drug residues from fingerprint impressions are extracted followed by analysis. The methodology of these hyphenated techniques toward forensic science applications is applied as to explore limits of detection, sensitivity, and selectivity of analytes as well as immediacy and efficiency of analysis. The application of nanomanipulation-coupled to nanospray ionization-mass spectrometry toward forensic science based applications is considered as future improvements to trace and ultra-trace analysis.

This work deals with the study of the drying-mediated assembly of colloidal gold nanoparticles (Au NPs) in mesoscale aggregation patterns and their manipulation by atomic force microscopy (AFM) on model surfaces. The assembly of NPs in mesoscale and complex aggregation patterns assisted by the wetting and the drying of complex fluids (suspensions of NPs, NPs/biopolymers mixed solutions) on homogeneous and heterogeneous molecular surfaces was studied. This issue is important, both for understanding fundamental processes of self-organization, and for generating new functional mesostructures. The drying of complex fluids often leads to the emergence of highly complex aggregation structures as shown and discussed in this work. The richness and the aesthetics of these complex structures generated by these interfacial phenomena reflect not only the bulk properties of fluids (different sizes and lengths- scales, kinetic changes in state), but more importantly, the coupling between the fluid properties and those of the substrate surface (wetting interactions, confinement, hydrodynamics). In the case of two important heterogeneous fluids which are Au NPs and polysaccharide solutions, these drying-mediated structure formation lead to the genesis of unusually large and highly ramified dendrites aggregation patterns. The growth mechanism and the critical parameters that control the morphogenesis of these complexes structures are addressed in this work. In addition, the aging mechanisms and kinetics of these structures that are metastable and evolve either through direct dislocation via clusters NPs mobility on the surface, or through undulation-induced roughning of the dendrite branches. To better understanding this NPs mobility and thus the dislocation mechanism of the aging, a detailed study based on the manipulation of NPs by atomic force microscopy in tapping mode (AFM) was developed. The threshold dissipated energy to manipulate (move) the NPs can be quantified according to the intrinsic parameters of the particle (size, shape, and chemical nature), the chemical nature and topography of the substrate, and finally the operating and environment conditions. This work enabled us to understand the mechanisms and characterize the critical parameters that may intervene in the dislocation (aging) of NPs-based functional structures, depending on the nature of the environment liquid and the substrate. Finally, this work proposes an approch of evaluation and of monitoring the stability and the aging of these aggregation structures, in particular, those formed from the drying of films and drops of nano-particles solutions (metal nanoparticles, blood: proteins, viruses ...).

Nanobelts are a new class of semiconducting metal oxide nanowires with great potential for nanoscale devices. The present research focuses on the manipulation of SnO₂ nanobelts suspended in ethanol using microfluidics and electric fields. Dielectrophoresis (DEP) was demonstrated for the first time on semiconducting metal oxide nanobelts, which also resulted in the fabrication of a multiple nanobelt device. Detailed and direct real-time observations of the wide variety of nanobelt motions induced by DEP forces were conducted using an innovative setup and an inverted optical microscope. High AC electric fields were generated on a gold microelectrode (~ 20 µm gap) array, patterned on glass substrate, and covered by a ~ 10 µm tall PDMS (polydimethylsiloxane) channel, into which the nanobelt suspension was introduced for performing the DEP experiments. Negative DEP (repulsion) of the nanobelts was observed in the low frequency range (< 100 kHz) of the applied voltage, which caused rigid body motion as well as deformation of the nanobelts. In the high frequency range (~ 1 MHz - 10 MHz), positive DEP (attraction) of the nanobelts was observed. Using a parallel plate electrode arrangement, evidence of electrophoresis was also found for DC and low frequency (Hz) voltages. The existence of negative DEP effect is unusual considering the fact that if bulk SnO₂ conductivity and permittivity values are used in combination with ethanol properties to calculate the Clausius Mossotti factor using the simple dipole approximation theory; it predicts positive DEP for most of the frequency range experimentally studied. A fluidic nanobelt alignment technique was studied and used in the fabrication of single nanobelt devices with small electrode gaps. These devices were primarily used for conducting impedance spectroscopy measurements to obtain an estimate of the nanobelt electrical conductivity. Parametric numerical studies were conducted using COMSOL Multiphysics software package to understand the different aspects of the DEP phenomenon in nanobelts. The DEP induced forces and torques were computed using the Maxwell Stress Tensor (MST) approach. The DEP force on the nanobelt was calculated for a range of nanobelt conductivity values. The simulation results indicate that the experimentally observed behavior can be explained if the nanobelt is modeled as having two components: an electrically conductive interior and a nonconductive outer layer surrounding it. This forms the basis for an explanation of the negative DEP observed in SnO₂ nanobelts suspended in ethanol. It is thought that the nonconductive layer is due to depletion of the charge carriers from the nanobelt surface regions. This is consistent with the fact that surface depletion is a commonly observed phenomenon in SnO₂ and other semiconducting metal oxide materials. The major research contribution of this work is that, since nanostructures have large surface areas, surface dominant properties are important. Considering only bulk electrical properties can predict misleading DEP characteristics.

Étude de la croissance de nanofils de SiGe par dépôt chimique en phase vapeur et caractérisation par microscopie à force atomique. Les nanofils semi-conducteurs constituent des briques de bases au potentiel prometteur pour l'amélioration des dispositifs du futur. D'autre part, l'alliage SiGe permet de contrôler les propriétés électroniques de la matière telles que les mobilités des porteurs et la largeur de bande. Dans le cadre de ce travail de thèse, nous étudions les mécanismes de croissance catalysée de nanofils de SiGe et développons des méthodes de caractérisation de nanofils par AFM.Dans un premier temps, la croissance par CVD de nanofils de SiGe est étudiée en utilisant l'or comme catalyseur. Nous étudions l'influence du HCl en phase gazeuse qui permet un contrôle de la croissance de nanofils de SiGe et modélisons son action.Dans un deuxième temps, nous étudions la croissance de nanofils SiGe catalysée par siliciures compatibles CMOS, et la croissance de nanofils de Ge pur à basse température. Nous nous intéressons également à l'élaboration d'hétérostructures.Enfin, nous étudions le module de Young de NF unique de Si, GaN et ZnO par AFM et une nouvelle méthode de génération de potentiel piézoélectrique sur NF de GaN a été développée.