Littérature scientifique sur le sujet « Nanoscaled tech »

Nanotechnology is the use of matter on an atomic, molecular, and supramolecular scale for various purposes. Nanotechnology field of application is very much diverse which includes surface science, organic chemistry, molecular biology, semiconductor physics, energy storage, engineering, microfabrication, and molecular engineering. Its medical application ranges from biological devices, nano-electronic biosensors, and to future biological machines. The main issue nowadays for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials. Lot more functionalities can be added to nanomaterials by interfacing them with biological structures. The size of nanomaterials is similar most biological molecules and so useful for both in vivo and in vitro biomedical research and applications. The integration of nanomaterials with biology had paved path to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications and drug delivery vehicles.

Nanoscale science is a rapidly-developing, multidisciplinary field of science and research that combines engineering, chemistry, physics, biology, and information technology pushes and the boundary between the science and the technology required to conduct it. Nanoscale science involves investigating and working with matter on the scale of 1–100 microns and has broad societal implications for new technologies. It is estimated that the worldwide workforce necessary to support the field of nanoscale science and nanotechnology will be close to 2 million by 2015 (National Nanotechnology Initiative, 2005). With such rapid developments in nanoscale science and technology, it is becoming more incumbent upon K-12 science teachers to provide the learning experiences necessary for students to understand the principles that govern behavior at the nanoscale and develop the skills needed to apply these concepts to improve everyday life. While onlya limited amount of nanoscale curricular materials are available for K-12 and undergraduate education many important unanswered questions exist, including: How do science teachers learn to teach nanoscale science?

Gas sensors have been object of increasing attention by the scientific community in recent years. For the development of the sensing element, two major trends seem to have appeared. On one hand, the possibility of creating complex structures at the nanoscale level has given rise to ever more sensitive sensors based on metal oxides and metal–polymer combinations. On the other hand, gas biosensors have started to be developed, thanks to their intrinsic ability to be selective for the target analyte. In this review, we analyze the recent progress in both areas and underline their strength, current problems, and future perspectives.

Due to the development of high-tech industries, the modern world is characterized by the increased production and consumption of nanoparticles (NPs) and nanomaterials. Among produced metal nanoparticles, silver nanoparticles are widely used in everyday life products, cosmetics, and medicine. It has already been established that, in nanoscale form, many even inert materials become toxic. Therefore, the study of the toxicity of various substances in nanoscale form is an urgent scientific task. There is now a body of experience on the toxic effect of AgNPs. In the present review, the most well-known results obtained over the 2009–2021 period, including the own performance on the toxicity of silver NPs, are collected and analyzed. Along with the data reporting a certain level of toxicity of silver NPs, experiments that did not reveal any obvious toxicity of nanosized forms of silver are discussed. According to the performed studies, the toxicity of silver NPs is often caused not by NPs themselves but by silver ions, compounds used for nanoparticle stabilization, and other reasons. Based on the analysis of the collected data, it can be concluded that at actual levels of silver NPs used in everyday life, workplace, and medicine, they will not have strong toxic effects on a healthy adult body.

The utilization of anodized aluminum (Al) components would contribute greatly to combat against dry friction if good tribological properties could be attained. Despite its hardness, the wear rate of anodic coatings presents a major problem in many applications, including automotive, aerospace and high-tech industries. Recently, nanolayers of Ti demonstrated high tribological effectiveness and unusually low dry friction on anodic coatings. However, few researchers focus on the tribological characterization of nanolayers of other elements. In this study, nanolayers of Ti, Zr, Hf, Cu, Cr, Nb and Sn were deposited on anodized 1050 and 6082 alloys by magnetron sputtering and Atomic Layer Deposition. Major attention was devoted to surface roughness and hardness measurements, because of their importance for static friction. The results showed that structural, chemical and other intrinsic properties of nanolayers of Group IVB elements in many cases led to significant friction reduction, when compared to those of Cu, Cr and Hf. Nanolayers of 15 nm to 75 nm thicknesses appeared most effective tribologically, while 180 nm or thicker layers progressively lost their ability to sustain low dynamic friction. Deposition of nanoscale structures could provide advantages for the anodized Al industry in protection against incidental friction and wear.

Digital speckle pattern interferometry (DSPI) is an advanced technique for both in-plane and out-of-plane deformation measurements of diffuse surfaces in nanoscale. It has been widely used in aerospace engineering and other high-tech industries due to the advantages of non-contact, high-accuracy and full-field measurement. Traditionally, DSPI uses temporal phase shifting method to achieve precise deformation measurement, but it is only suitable for quasi-static deformation. Spatial-carrier method is another effective phase retrieval method used in DSPI and its validity has been verified in some DSPI setups. DSPI with spatial-carrier method enjoys the advantages of simple optical arrangement, easy operation, and above all, high-speed measurement of deformation. This paper introduces a dual-beam spatial-carrier digital speckle pattern interferometry system, with which in-plane and out-of-plane deformations can be measured simultaneously as well as quickly. In the optical setup, two lasers are employed to illuminate the measured object with different illumination angles, and two single-mode fibers server as carriers to transmit the reference beams. In-plane and out-of-plane deformations can be obtained by combining the phase maps of both channels. Theoretical discussion and experimental analysis are both presented.

The advent of nanoscientific applications in modern life is swiftly in progress. Nanoscale innovation comes with the pressing need to provide citizens and learners with scientific knowledge for judging the societal impact of nanotechnology. In rising to the challenge, this paper reports the developmental phase of a research agenda concerned with building and investigating a virtual environment for communicating nano-ideas. Methods involved elucidating core nano-principles through two purposefully contrasting nano “risk” and “benefit” scenarios for incorporation into an immersive system. The authors implemented the resulting 3D virtual architecture through an exploration of citizens' and school students' interaction with the virtual nanoworld. Findings suggest that users' interactive experiences of conducting the two tasks based on gestural interaction with the system serve as a cognitive gateway for engendering nano-related understanding underpinning perceived hopes and fears and as a stimulating pedagogical basis from which to teach complex science concepts.

Negli ultimi tre decenni l'elettronica delle telecomunicazioni mobili ha subito un grande miglioramento, questo ramo dell'elettronica si è rivelato una delle principali forze trainanti nello sviluppo delle nuove tecnologie CMOS. in tutto il mondo richiedono dispositivi portatili estremamente performanti, più veloci, più affidabili, a basso consumo energetico. Questa situazione è diventata estremamente favorevole per lo sviluppo di dispositivi digitali ad alte prestazioni in grado di raggiungere velocità e capacità di memoria prima incredibili. Anche i blocchi di costruzione analogici devono essere integrati in nodi profondamente ridimensionati, al fine di adattarsi ai circuiti integrati digitali . Il primo compito di questo lavoro di tesi è stata l'implementazione e la misurazione di diversi circuiti integrati in due nodi tecnologici profondamente scalati come CMOS bulk a 28 nm e FinFET (Fin Field Effect Transistor) a 16 nm. In particolare, il secondo di questi introduce novità sulla struttura del transistor utilizzato per implementare i circuiti. Ciascun circuito realizzato incontra diverse difficoltà dovute al particolare comportamento di tali tecnologie avanzate, in particolare in termini di basso intrinsic gain e basso output voltage swing come conseguenza della bassa tensione di alimentazione. Ho lavorato nel progetto FinFET16 con il compito principale di realizzare e validare il layout di un filtro analogico Super-Source-Follower fully-differential del 4° ordine. Dopo le misurazioni, il filtro raggiunge 15,1 dBm IIP3 in banda a 10 MHz e toni di ingresso 11 MHz, con un consumo energetico di 968 µW da una singola tensione di alimentazione da 1 V. Il rumore integrato in banda è 85,78 µVrms per una figura di merito complessiva di 162,8 dB (j-1) che supera lo stato dell'arte dei filtri analogici. Ho anche collaborato come layoutista in altri due progetti realizzati con tecnologia CMOS a 28 nm. Il primo è stato il progetto PRIN Brain28nm che riguarda l'implementazione di una catena di acquisizione del segnale neurale. L'obiettivo di questo lavoro era la realizzazione di un biosensore che utilizza la struttura EOMOSFET con il nodo tecnologico CMOS a 28 nm. L'utilizzo di questa tecnologia rende questo circuito più competitivo rispetto ai biosensori presenti in letteratura. L'ultimo progetto è stato il progetto Pignoletto realizzato in collaborazione con RedCat Devices. Esso riguarda l'implementazione e l'analisi teorica di due diverse tipologie di circuiti integrati misurati sotto irraggiamento: due celle digitali e un convertitore da analogico a digitale. Nella seconda parte del mio terzo anno ho iniziato un'attività lavorativa presso la sede di Pavia della AMS come validation engineer. Questa azienda è leader mondiale nel campo dell'Automotive Interior Lightning. ll progetto che sto portando avanti prevede la realizzazione di un setup di validazione per un IC, al fine di verificare il corretto svolgimento delle molteplici funzioni per le quali questo chip è progettato. Una prima analisi, utile allo studio preliminare per la realizzazione del setup, è stata effettuata attraverso l'utilizzo di un FPGA su cui è stato caricato il codice che realizza la parte logica dell'IC utilizzando il software Quartus. Una volta validato il corretto funzionamento dell'FPGA, attraverso l'utilizzo di un microcontrollore STM32, sono state testate e correttamente validate diverse configurazioni e funzioni. Lo scopo finale di questa attività, che proseguirà nei prossimi mesi, è la validazione di alcune modalità di comunicazione tra diversi dispositivi, fondamentali per l'interfaccia dell'IC con gli standard automotive, e la creazione di una versione aggiornata del codice FPGA e della sua successiva verifica. Questa attività sembra essere una novità nel campo del design di circuiti integrati perché potrebbe permettere di evidenziare eventuali problemi.
In the last three decades Mobile Telecommunication (TLC) electronics has undergone a great improvement, this limited branch of electronics proved to be one of the major driving motor in the development of the new Complementary Metal-Oxide-Semiconductor (CMOS) technologies. People all around the world ask for extremely performing portable devices, faster, more reliable, low power consuming and with impressive memory capability. This situation has become extremely favorable for the development of high performance digital devices which are able to reach speed and memory capability previously unbelievable. Also analog building blocks must be integrated in deeply down-scaled node, in order to adapt with digital integrated circuits (ICs). First task of this thesis work was the implementation and measurement of different integrated circuits in two deep sub-micron technology nodes as 28nm bulk-CMOS and 16nm FinFET (Fin Field Effect Transistor). In particular the second one of these introduces novelty about the structure of transistor used to implement the circuits. Each circuit created faces various difficulties due to the particular behaviour of such advanced technologies, in particular in terms of low intrinsic gain and limited signal swing as consequence of low supply voltage. I worked in FinFET16 project with the main task to realize and validate the layout of a 4^th Order Fully-Differential Super-Source-Follower Analog Filter. After measurements the filter achieves 15.1 dBm in-band IIP3 at 10 MHz & 11 MHz input tones, with 968 µW power consumption from a single 1V supply voltage. In-band integrated noise is 85.78 µVrms for an overall Figure-of-Merit of 162.8 dB (j-1) which outperforms analog filters State-of-the-Art. I also collaborated as layoutist in other two projects realized with 28nm CMOS technology. The first one was the PRIN Brain28nm project that concerns the implementation of a neural signal acquisition chain. The goal of this work was the realization of a biosensor that uses the EOMOSFET structure with the 28nm CMOS technological node. The use of this technology makes this circuit more competitive when compared to the biosensors present in literature. The last one was Pignoletto project realized in collaboration with RedCat Devices. It concerns the implementation and theorical analysis of two different typologies of ICs measured under radiation: two digital cells and one Analog to Digital Converter. Under radiation measurements will be realize in January 2023. In the second part of my third year I started a work activity in Pavia site of AMS-Osram S.r.l as validation engineer. This company is a world leader in the field of optical sensors and the application of the latter in the automotive sector. The project I am carrying out involves the creation of a validation setup for an IC, in order to verify the correct performance of the multiple functions for which this chip is designed. A first analysis, useful for the preliminary study for the realization of the setup, was carried out through the use of an FPGA (Cyclone1000) on which the code that realizes the logic part of the IC was loaded using the Quartus software. Once the correct operation of the FPGA was validated, through the use of an STM32 micro-controller, various configurations and functions have been tested and correctly validated. The final purpose of this activity, which will continue in the coming months, is the validation of some communication methods between different devices, fundamental for the interface of the IC with automotive standards, and the creation of an updated version of the FPGA code and its subsequent verification. This activity appears to be a novelty in the field of integrated circuit design as it would allow to highlight problems and malfunctions of the circuit.

In the proposed chapter, the authors will present an overview about the role of the main transparent conductive oxides as functional coatings and its incorporation into emerging large area flexible photovoltaic technologies. In particular, the authors will describe the state of the art in this area, with the highlight of establishing the importance of using transparent conductive oxides as an essential part of an industrial chain. In this sense, it will be emphasized the main requirements of transparent conductive oxides, the main deposition techniques employed for its fabrication, the different material alternatives that emerge as substitutes of conventional ones and, finally, the evaluation of the main risks found when the coatings will be incorporated in an industrial production chain of flexible devices.

The advent of nanoscientific applications in modern life is swiftly in progress. Nanoscale innovation comes with the pressing need to provide citizens and learners with scientific knowledge for judging the societal impact of nanotechnology. In rising to the challenge, this paper reports the developmental phase of a research agenda concerned with building and investigating a virtual environment for communicating nano-ideas. Methods involved elucidating core nano-principles through two purposefully contrasting nano “risk” and “benefit” scenarios for incorporation into an immersive system. The authors implemented the resulting 3D virtual architecture through an exploration of citizens' and school students' interaction with the virtual nanoworld. Findings suggest that users' interactive experiences of conducting the two tasks based on gestural interaction with the system serve as a cognitive gateway for engendering nano-related understanding underpinning perceived hopes and fears and as a stimulating pedagogical basis from which to teach complex science concepts.

As the world is modernizing, it is noteworthy to mention photonics and its categorization based on size. Despite the components of light being invisible to the human eye, nature never ceases to amaze us with its idiosyncratic phenomenon. Furthermore, the manipulation of the matter is confined to the nanoscale as a part of the progression. Adding nanotechnology to photonics emerges out as nanophotonics which is the cutting-edge tech of the twenty-first century. Human beings have acclimated to the concept of photonics, furthermore, nanophotonics is the science of miniaturization study, potentially helping the technology to modify itself into the sophistication of the equipment and thereby be of assistance in various disciplines of science and technology. One can illustrate nanophotonics by considering the fabrication processes of nanomaterials. In variegated applications, these nanoscale processes will refine and produce structures with high precision and accuracy. Meanwhile, groundbreaking inventions and discoveries have been going around, from communications to data processing, from detecting diseases to treating diseases at the outset. As one stresses on the idea of nanophotonics, it never reaches a dead-end, however, this explains how vast the universe and each of the components co-existing are infinitesimally beyond humans' reach. Nevertheless, nanophotonics and its applications bring about remarkable multidisciplinary challenges which require proficient and well-cultivated researchers. Despite the fact it has several advantages, it carries its downside, which requires a detailed analysis of any matter. Using state-of-the-art technology, one can constrict light into a nanometer scale using different principle methodologies such as surface plasmons, metal optics, near field optics, and metamaterials. The distinctive optical properties of nanophotonics call out specific applications in the electronics field such as interaction chips, tiny devices, transistor filaments, etc. When compared to conventional electronic integrated circuits, the pace at which data using nanophotonic devices is sent is exceptionally fast, accurate, and has a better signal processing capability. As a result of the integration of nanotechnology with photonic circuit technology, high-speed data processing with an average processing speed on the order of terabits per second is possible. Furthermore, nano-integrated photonics technology is capable of comprehensive data storage and processing, which inevitably lays the groundwork for the fabrication, quantification, control, and functional requirements of novel optical science and technology. The majority of applications include nanolithography, near-field scanning optical microscopy, nanotube nanomotors, and others. This explains about the working principle, different materials utilized, and several other applications for a better understanding.

The growing interest in nanoscale energy transfer research and funding in mechanical engineering departments far out weighs the availability for formal training of fundamental ideas and concepts in this area. Although several universities offer formal graduate courses in nanoscale energy transfer, these courses are often a survey of current research and are typically geared to graduate students or advanced undergraduates with a stonger physics background than the typical undergraduate engineering student. The goal of this paper is to outline a course that is designed to teach fundamental nanoscale energy transfer concepts to the undergraduate engineering student who has not taken advanced physics courses outside of the ABET approved mechanical engineering curriculum. A survey of different nanoscale energy transfer courses from various institutions around the world is discussed in specific context of the benefits for the typical mechanical engineering undergraduate. The limited textbooks that are available on the subject are also discussed. An outline of fundamental topics in quantum physics, statistical mechanics, and solid state physics is presented as important concepts that the typical undergraduate should understand in order to understand basic research and principles of nanoscale energy transfer. Important phenomena and techniques in nanoscale energy transfer research are also discussed. This course was taught as an undergraduate and graduate engineering elective at the University of Virginia in the spring semester of 2008.

Emulsification is an important process in various fields including foods, pharmaceuticals, cosmetics, and chemicals. Emulsification operation is commonly conducted using conventional emulsification devices, such as high-speed blenders, colloid mills, high-pressure homogenizers, and ultrasonic homogenizers. However, these emulsification devices result in the production of polydisperse emulsions with wide droplet size distributions and poor controllability in droplet size and its distribution. In contrast, monodisperse emulsions consisting of monosize droplets have received a great deal of attentions over the past decade due to their high-tech applications, e.g., monosize microparticles as spacers for electronic devices and monosize micro-carriers for drug delivery systems (DDS). Our group proposed microchannel (MC) emulsification as a promising technique to produce monodisperse emulsions in the mid 1990s. Micro/Nanochannel (MNC) emulsification enables generating monosize droplets with the smallest coefficient of variation (CV) of below 5% using MC and nanochannel (NC) arrays of unique geometry. The resultant droplet size, which ranged from 0.5 to 200 μm, can be precisely controlled by channel geometry. Droplet generation for MNC emulsification is very mild and does not require any external shear stress; a dispersed phase that passed through channels is transformed spontaneously into monosize droplets inside a continuous-phase domain. The aim of this paper is to present recent developments in MNC emulsification chips, particularly focusing on asymmetric straight-through MC arrays for large-scale production of monodisperse emulsions. Asymmetric straight-through MC array chips were fabricated using a silicon-on-insulator wafer. Numerous asymmetric straight-through MCs each consisting of a microslot and a narrow MC were positioned in the central region of the chip. Monosize droplets were stably generated via asymmetric straight-through MCs at high production rates. Below a critical droplet production rate, monosize droplets were generated via asymmetric straight-through MCs, with droplet size and size distribution independent of the droplet productivity. The use of a large asymmetric straight-through MC array chip achieved the mass production of monosize tetradecane oil droplets at ∼1 L/h. The simulation results using CFD (computational fluid dynamics) agreed well with the experimental results and provided useful information, such as the movement of the oil-water interface during droplet generation. Monosize submicron droplets were also obtained using NC emulsification chips made of single-crystal silicon.

Chemical-mechanical planarization (CMP), a surface preparation process used widely in integrated circuits manufacture, is currently the leading nanoscale manufacturing process worldwide, with an annual economic impact well in excess of $1 billion. Originally developed for glass polishing, CMP is used by the microelectronics industry to create silicon, silicon oxide, tungsten and copper surfaces with average roughnesses of O(10 mm). The process typically involves shearing a dilute abrasive silica or ceria nanoparticle-laden “slurry” between a compliant rough surface (the “pad”) and the surface to be polished (the “wafer”). The composition of the slurry can greatly affect material removal rates. Despite its importance, however, a lot still remains to be discovered about the fundamental mechanisms involved in this process. A multidisciplinary effort at Georgia Tech has focused upon the interfacial mechanics of this process and how nanoparticles chemomechanically wear SiO2, Si and Cu surfaces. It has been found, for example, that the wear rate of dielectric varies approximately as the particle diameter. The entrapment of particles at the asperity/dielectric interface is thought to produce the polishing, but the exact nature of this interaction is still unknown. An evanescent-wave visualization technique has therefore been developed to visualize the dynamics of fluorescent 300–500 nm diameter colloidal silica and polystyrene particles within a particle diameter of the “wafer” surface in a simplified model pad-wafer geometry. The technique has been used for the first time to the authors’ knowledge to directly measure the velocity and concentration of the interfacial particles—which presumably interact with and wear the wafer. Although the pad speeds in these studies are much lower than those encountered in the actual CMP process, the initial results suggest that there is negligible “slip” between the particle and fluid phase velocities at the wafer surface. The number of particles at the wafer surface appears, however, to be strongly affected by particle properties, including particle density and size.