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1
Lin, Qin Hong, et Zheng Shang Da. « Monte Carlo Model of Optomechanical Tolerance for Lens Assembly ». Advanced Materials Research 571 (septembre 2012) : 574–78. http://dx.doi.org/10.4028/www.scientific.net/amr.571.574.
Texte intégralRésumé :
Research on the opto-mechanical tolerance analysis for lens optical system is presented. Take a traditional "drop-in" assembly for example. How fabrication tolerances transfer to tolerances of optical elements is analysed. Finally, Monte-Carlo model for opto-mechanical tolerances is proposed, which considers both the fabrication and assembly process.
2
Yang, Zhen, Xinmin Guo, Songtao Lu, Yong Zhang, Haili Hu, Kaichang Lu et Jianlong Zhang. « Investigation of Stray Radiation Suppression in Infrared Imaging System Using a Novel Broadband and High-Absorption Ceramic Coating ». Applied Sciences 11, no 11 (27 mai 2021) : 4952. http://dx.doi.org/10.3390/app11114952.
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Aiming at addressing the vulnerability of the infrared imaging opto-mechanical system to stray radiation interference caused by an external laser, a new method with a broadband and high-absorptivity ceramic coating on the inner wall of the system is proposed to reduce the stray radiation intensity, which is helpful to improve the imaging quality of the detection image. Based on plasma electrolytic oxidation (PEO) technology, the preparation method and properties of a novel ceramic coating are studied, and a long-wave infrared imaging optical system with high-absorption ceramic coating is designed and developed. It is verified for the first time that the high-absorption ceramic coating can suppress the stray radiation in the infrared opto-mechanical system, and the effect of laser incident power and angle on the stray radiation is investigated. The experimental results show that the ceramic coating can achieve 95.4% high absorption in the wavelength range of 0.2–16 μm, which can obviously suppress the stray radiation in the opto-mechanical system of infrared imaging caused by laser. The calculation of the stray radiation suppression ratio shows that, compared with the case without coating, the stray radiation intensity in the system can be reduced by 70% using the ceramic coating.
3
Kurcsics, Mark, Luzia Hahn et Peter Eberhard. « Transient Structural, Thermal and Optical Performance (STOP) Analysis with Accelerated Thermomechanical Computation ». EPJ Web of Conferences 309 (2024) : 03025. http://dx.doi.org/10.1051/epjconf/202430903025.
Texte intégralRésumé :
Mechanical and thermal disturbances in optical systems are attracting increasing attention as accuracy requirements rise. For this reason, it is necessary to consider these disturbances at an early stage in the design process. This can be done by a holistic multiphysical opto-thermo-mechanical simulation. Such an approach is presented with a focus on efficient thermomechanical computation through a quasi-static approximation.
4
Carrasco, Sergio, et Miguel Orszag. « Weak Value Amplification of Photons in Optical Nonlinear Medium, Opto-Mechanical, and Spin-Mechanical Systems ». Photonics 11, no 4 (23 mars 2024) : 291. http://dx.doi.org/10.3390/photonics11040291.
Texte intégralRésumé :
A measurement of an observable A performed on a quantum system that is initially prepared in a state ρi, followed by a probabilistic procedure that leaves the system in a final state ρf, a process often referred as state postselection (or filtering process), can yield, on average, anomalous measurement results, i.e., values that may exceed the eigenvalue range of the observable being measured or be complex numbers. There is, therefore, an amplification effect of the average measurement result, i.e., the effect of the system on the measurement device is increased. When the coupling between the system and the measurement device satisfies some weakness conditions, the amplification effect occurs due to the weak value of the operator A. In this article, the amplification effect due to the postselection process is reviewed, and theoretical proposals and experiments published in the recent literature on the field are commented on. The emphasis is made on interactions occurring in optical nonlinear media and opto-mechanical and spin-mechanical systems, in which the amplification of number operators takes place.
5
Xia, Huang et Zhao. « A New Design of an MOEMS Gyroscope Based on a WGM Microdisk Resonator ». Sensors 19, no 12 (21 juin 2019) : 2798. http://dx.doi.org/10.3390/s19122798.
Texte intégralRésumé :
In this paper, we present a new design for a micro-opto-electro-mechanical (MOEMS) gyroscope based on a whispering-gallery mode (WGM) microdisk resonator and MEMS resonator. The mechanical characteristics, frequency split, and quality factor (Q) of the MEMS resonator; the optical characteristics, Q value, and coupling regimes of the WGM resonator; and the coupling between the two resonators were analyzed. Its operation principle—the transformation process from angular velocity to the resonance wavelength of the WGM resonator—is presented at same time. Next, the analysis conclusions were validated with the help of simulations in ANSYS and FDTD (Finite-Difference Time-Domain) Solutions. Afterwards, some key specifications were estimated based on the results of simulations. Lastly, the fabrication process is detailed.
6
Smith, J. A., D. Jevtics, B. Guilhabert, M. D. Dawson et M. J. Strain. « Hybrid integration of chipscale photonic devices using accurate transfer printing methods ». Applied Physics Reviews 9, no 4 (décembre 2022) : 041317. http://dx.doi.org/10.1063/5.0121567.
Texte intégralRésumé :
Transfer printing is becoming widely adopted as a back-end process for the hybrid integration of photonic and electronic devices. Integration of membrane components, with micrometer-scale footprints and sub-micron waveguide dimensions, imposes strict performance requirements on the process. In this review, we present an overview of transfer printing for integrated photonics applications, covering materials and fabrication process considerations, methods for efficient optical coupling, and high-accuracy inter-layer alignment. We present state-of-the-art integration demonstrations covering optical sources and detectors, quantum emitters, sensors, and opto-mechanical devices. Finally, we look toward future developments in the technology that will be required for dense multi-materials integration at wafer scales.
7
Sokkar, T. Z. N., K. A. El‐Farahaty, M. A. El‐Bakary, M. I. Raslan et F. E. Hanash. « A novel dynamic opto‐thermo‐mechanical stress testing device 2 : In situ stretching process of polymeric fibers ». Microscopy Research and Technique 81, no 11 (8 octobre 2018) : 1261–67. http://dx.doi.org/10.1002/jemt.23132.
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Chang, Xia, Li Song, Chun Wang et Ai Zhang. « A Control and Simulation Method for Space-based Opto-mechanical Structures Using Uniform Scanning ». Journal of Physics : Conference Series 2395, no 1 (1 décembre 2022) : 012046. http://dx.doi.org/10.1088/1742-6596/2395/1/012046.
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Abstract To achieve high-precision imaging in the calibration area of a sub-satellite point, this paper proposes a method for assessing the scanning accuracy and how it affects the agility of the maneuvering process. In addition, simulations and experimental validation are also conducted using a position-velocity dual-loop control algorithm. The design is based on the control theory and the operating characteristics of the actual flexible scanning mechanism, the control law is designed using the control method based on the permanent magnet synchronous motor model, and the interference is simulated and analyzed. The results show that the design can combine the control performance indexes of practical applications and meet the requirements of in-orbit high-precision scanning, which can provide a reference for the subsequent development of space high-precision scanning control.
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Невлюдов, І. Ш., О. О. Чала, О. І. Филипенко et І. В. Боцман. « Model of simulation of the process of formation of functional surfaces of micro-opto-electro-mechanical systems’ components ». Системи озброєння і військова техніка, no 2(62), (8 juin 2020) : 73–82. http://dx.doi.org/10.30748/soivt.2020.62.10.
Texte intégralRésumé :
The subject of the article is to establish the relationships between the parameters of formation the functional surfaces of the substrates of micro-opto-electro-mechanical systems’ (MOEMS) components and their physical and technological parameters. Objectives: to increase the reliability and reproducibility of the received information, reduce the complexity of the technological process of forming, by modeling the dependences of the ratios of physical and technological parameters of forming the functional surfaces of the substrates of MOEMS components for the forming process. The methods are used: methods of experiment planning and computer processing of experimental data, mathematical models, digital computer modeling of technological processes. The following results were obtained: a mathematical model was proposed, which was used to model the influence of physical and technological parameters of the functional surfaces of the substrates of MOEMS components on their formation, with the receipt of prototypes. The results can be used in the development of technological processes of production, as substrates of functional components of MOEMS, and other functional elements for various technological purposes. A mathematical model is obtained, which allows predicting the degree of influence of physical and technological parameters of the technological process on the parameters of formation of functional surfaces of substrates of MOEMS components. Conclusions. The scientific novelty of the results is as follows: a mathematical model that has found practical implementation for computer digital modeling in the development of technological processes for the production of functional surfaces of substrates of MOEMS components is proposed, in which, unlike the existing ones, it is possible to predict the degree of influence of physical substrates of MOEMS components, which allows to plan the process of formation, increase the reproducibility of results and reduce the complexity of the technological process.
10
Bablu K, Ghosh, et Ghosh Swapan K. « Optomechanics and Sensing Phenomena : An Analysis in Classical-quantum Relationship ». Compendium of Optics and Photonics 1, no 1 (28 août 2024) : 006–13. http://dx.doi.org/10.17352/cop.000002.
Texte intégralRésumé :
As a multi-approach sensing field optomechanics is primarily related to the interaction between optical and mechanical modes interaction. Light-matters dealings in linear to non-linear routes are trails of precision and Quantum Sensing (QS). Light is a wave-matter quantum entity from the classical Electromagnetic (EM) field in which matter is entangled with waves in space-time dimension. The interaction of electromagnetic radiation with the motion of objects and the gravity action is an energy perturbation and complex phenomenon. The energy-mass relation is like wave matter in which a possible link between classical and quantum mechanics is imperative for advanced opto-mechanical sensing. The quantization of mechanical energy and its interaction with light is a process that can be used for diverse sensing purposes. In this study light and gravity-related electromagnetic and mechanical system linkage has been elucidated systematically at macro and micro levels for optomechanical sensing system further development.
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Невлюдов, І. Ш., О. І. Филипенко, О. О. Чала et І. В. Боцман. « A method of monitoring the functional surfaces of the micro-opto-electro-mechanical systems’ components ». Наука і техніка Повітряних Сил Збройних Сил України, no 3(40), (12 août 2020) : 114–23. http://dx.doi.org/10.30748/nitps.2020.40.13.
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The article presents a method of control of functional surfaces of MOEMS elements of special purpose, which can be used in the technology of production of such structures. This method of non-destructive testing allows to obtain information about the parameters of the topology of the surface of functional structures, by eliminating the accompanying components in the interference signal. The method, in comparison with others, allows to increase the reliability of technological operations of production of functional surfaces of optical signal switches by more than 20% and to reduce labor costs up to 35%. Using the proposed method, it is possible to give recommendations for improving the technological process of manufacturing MOEMS functional surfaces, to ensure the specified values of their topology. The modeling by means of computer processing is performed in the paper in order to determine the extremes of the bands of interference images of the functional surfaces of MOEMS elements.
12
Hayat, Zain, Nizar Bchellaoui, Claire Deo, Rémi Métivier, Nicolas Bogliotti, Juan Xie, Malcolm Buckle et Abdel I. El Abed. « Fast Active Merging of Microdroplets in Microfluidic Chambers Driven by Photo-Isomerisation of Azobenzene Based Surfactants ». Biosensors 9, no 4 (1 novembre 2019) : 129. http://dx.doi.org/10.3390/bios9040129.
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In this work, we report on the development of a newly synthesized photoactive reversible azobenzene derived surfactant polymer, which enables active and fast control of the merging of microdroplets in microfluidic chambers, driven by a pulsed UV laser optical stimulus and the well known cis-trans photo-isomerisation of azobenzene groups. We show for the first time that merging of microdroplets can be achieved optically based on a photo-isomerization process with a high spatio-temporal resolution. Our results show that the physical process lying behind the merging of microdroplets is not driven by a change in surface activity of the droplet stabilizing surfactant under UV illumination (as originally expected), and they suggest an original mechanism for the merging of droplets based on the well-known opto-mechanical motion of azobenzene molecules triggered by light irradiation.
13
Gholamzadeh, Reza, Milad Gharooni, Hassan Salarieh et Javad Akbari. « Design and fabrication of a micro-opto-mechanical-systems accelerometer based on intensity modulation of light fabricated by a modified deep-reactive-ion-etching process using silicon-on-insulator wafer ». Journal of Vacuum Science & ; Technology B 40, no 4 (juillet 2022) : 043001. http://dx.doi.org/10.1116/6.0001779.
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Accelerometers that work based on intensity modulation of light are more sensitive, economically feasible, and have a simpler fabrication process compared to wavelength modulation. A micro-opto-electro-mechanical-system accelerometer based on intensity modulation of light is designed and fabricated. A movable shutter that is attached to the proof mass is designed to change the intensity of light. Moreover, the mechanical part is designed to improve the overall sensitivity and linear behavior in the measurement range. The designed accelerometer is fabricated by a deep-reactive-ion-etching (DRIE) process. The DRIE process used in this report is based on a Bosch-like process, which uses [Formula: see text] and a mixture of [Formula: see text], [Formula: see text], and [Formula: see text] gases in etching and passivation subsequences, respectively. This method has a lower plasma density and a higher base pressure and causes higher verticality, which results in lower optical efficiency loss in comparison with the Bosch process. Furthermore, the functional characteristics of the accelerometer are derived with analytical and numerical methods, and the results are compared. The functional characteristics of the accelerometer are as follows: a resonant frequency of 0.56 kHz, a mechanical sensitivity of [Formula: see text], an optical sensitivity of [Formula: see text], an overall sensitivity of [Formula: see text], a footprint of [Formula: see text], a measurement range of [Formula: see text], a mechanical cross axis sensitivity of [Formula: see text], and an overall cross axis sensitivity of [Formula: see text]. These functional characteristics make the design appropriate for a large range of applications.
14
Morales-Bonilla, Samuel, Isaac I. Mota-Díaz, Janna Douda, Ariel Fuerte-Hernández, Juan Pablo Campos-López et Carlos Torres-Torres. « Influence of Asymmetric Agglomerations Effects over the Photothermal Release of Liposome-Encapsulated Nanodiamonds Assisted by Opto-Mechanical Changes ». Symmetry 15, no 3 (22 mars 2023) : 775. http://dx.doi.org/10.3390/sym15030775.
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An analysis of optical effects exhibited by blood plasma under healthy/unhealthy conditions, and of the penetrating evolution of nanovehicles conformed by nanodiamonds (NDs) encapsulating liposomes (L) within these biofluids, is presented. Optical ablation of liposome clusters was actuated and controlled by a standard two-wave mixing (λ = 532 nm, τp = 4 ns) laser light method. Radiant time exposure effects (30 min) and threshold laser energy parameters (250 mJ/cm2 numerical; 181 mJ/cm2 experimental) necessary to release NDs were identified and confirmed with similar experiments in the literature. Interactions during the sedimentation process between nanovehicles and the laser beams barrier were considered as the principal thermal damage process to achieve the release and transportation of drugs within these static fluids. The mechanical response during the release of NDs focuses on the temperature propagation, dynamic effects of nanovehicles associated with the diffusion coefficient, and some agglomeration effects. The principal findings of this research concern the threshold temperature (51.85 °C) of liposomes for the release of NDs with respect to that typically quoted in the literature (40–70 °C) for pure liposomes. The assessment of the release of NDs focuses on the numerical magnitude of Quantum Yield. Furthermore, the optical contrast enhancement was associated with NDs size agglomerations and the healthy/unhealthy conditions of fluids. This research aims to be a first proof approximation for delivery and transportation approaches to guide and interpret outcomes when combined with the vectorial nature basis of laser light and further effects once the cargo is retained in the fluids.
15
Pavlovskyy, Yuriy. « Laser surface modification of materials ». Ukrainian Journal of Mechanical Engineering and Materials Science 7, no 1-2 (2021) : 54–60. http://dx.doi.org/10.23939/ujmems2021.01-02.054.
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To develop any process of laser technology, you need to solve 3 problems: 1) What are the properties of the interaction of laser radiation with matter must be selected to achieve the goal (resonant – non-resonant, absorption-scattering, photo- or thermal absorption, heating, hardening, melting, softening, evaporation, decomposition, coagulation, etc.); 2) What type of laser source should be used to achieve this goal (wavelength, operation mode – continuous or pulse-frequency, power, pulse duration, transverse energy distribution in the beam, coherence, monochromaticity, polarization, etc. taking into account the reliability, stability of the process and its value, and how to calculate and verify these parameters ?; 3) What are the requirements for the transverse and longitudinal shape of the beam and what opto-mechanical, opto-electronic and other systems are needed to solve this problem? Successful solution of these problems hardens the high quality of the result of the application of laser technology of materials processing. The aim of this work is to show the effectiveness of laser surface treatment of materials on their micromechanical properties. The surface of the samples was treated with laser radiation using a pulsed neodymium laser YAG: Nd. Vickers microhardness measurements were then performed. The surface of silicon carbide was irradiated with a laser beam with different technical parameters. The micromechanical characteristics of the treated samples were studied and their comparison with the source material was made. Suggestions for laser modification of mechanical properties of superhard materials are made. Alloying of aluminum with titanium nitride impurities by pulsed laser irradiation was performed. A significant increase in microhardness in the field of laser fusion of titanium nitride nanopowder into the aluminum matrix was revealed. We have thus shown that laser treatment of structural and functional materials is an effective method of controlling their properties. A set of experimental studies, in particular, structural, optical, and magnetic, will be conducted to physically substantiate the established results. In this paper, we have expressed our views, citing well-known literature sources.
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Zhou, Ya-Fei, Li-Guo Qin, Jie-Hui Huang, Li-Li Wang, Li-Jun Tian, Zhong-Yang Wang et Shang-Qing Gong. « Electrically controlled optical nonlinear effects in the hybrid opto-electromechanical system with the cross-Kerr effect ». Journal of Applied Physics 131, no 19 (21 mai 2022) : 194401. http://dx.doi.org/10.1063/5.0091211.
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We theoretically study the nonlinear optical phenomena including optical stability state and four-wave mixing (FWM) process in a hybrid opto-electromechanical system with the cross-Kerr (CK) effect. The hybrid system consists of an optomechanical cavity in which the cross-Kerr (CK) effect and Coulomb interaction are simultaneously introduced by the CK medium and the mechanical resonator capacitively coupling to an external circuit, respectively. The CK interaction induces a tristability behavior of the mean intracavity photon number, which can be modulated by the strength of the CK effect and electrically controlled by the voltage on the capacitor. In addition, we give the effects of the optomechanical, CK, and Coulomb coupling strengths on the FWM of the output field. The results show that the voltage can be employed to electrically engineer the optical nonlinear phenomena.
17
Xia, Dunzhu, Bing Zhang, Hao Wu et Tao Wu. « Optimization and Fabrication of an MOEMS Gyroscope Based on a WGM Resonator ». Sensors 20, no 24 (18 décembre 2020) : 7264. http://dx.doi.org/10.3390/s20247264.
Texte intégralRésumé :
In this paper, the characterization of a whispering gallery mode (WGM) resonator applied in a novel micro-opto-electro-mechanical system (MOEMS) gyroscope was investigated. The WGM optical transmission coupling model was analyzed and compared by adjusting key parameters, such as the cavity radius, the waveguide width, and the gap between them for silicon and silicon nitride materials in simulations, which will greatly affect the quality factor (Q) of the WGM resonator. Furthermore, the structural parameters of the disk resonant gyroscope were also optimized. Then, the fabrication process was optimized to overcome the difficulties in the realization of micro-optical devices. Finally, a gyroscope prototype with the integrated WGM resonator was verified experimentally. The scale factor and bias instability performance of the MOEMS gyroscope was 2.63 mv/°/s and 4.0339°/h, respectively.
18
Bajpai, Gaurav, Igamcha Moirangthem, Shuvam Sarkar, Sudipta Roy Barman, C. P. Vinod, Shubhra Bajpai, Sk Riyajuddin et al. « Role of Li+ and Fe3+ in modified ZnO : Structural, vibrational, opto-electronic, mechanical and magnetic properties ». Ceramics International 45, no 6 (avril 2019) : 7232–43. http://dx.doi.org/10.1016/j.ceramint.2019.01.004.
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Giese, C., P. Quellmalz et P. Knittel. « Development of All-Diamond Scanning Probes Based on Faraday Cage Angled Etching Techniques ». MRS Advances 5, no 35-36 (2020) : 1899–907. http://dx.doi.org/10.1557/adv.2020.147.
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ABSTRACTWe are proposing a novel fabrication method for single crystal diamond scanning probes for atomic force microscopy (AFM), exploiting Faraday cage angled etching (FCAE). Common, oxygen-based, inductively coupled plasma (ICP) dry etching processes for diamond are limited with respect to the achievable geometries. The fabrication of freestanding micro- and nanostructures is therefore challenging. This is a major disadvantage for several application fields e.g., for realizing scanning magnetometry probes based on nitrogen vacancy (NV) centres and capable of measuring magnetic fields at the nanoscale. Combining a planar design with FCAE and state-of-the-art electron beam lithography (EBL) yields a reduction of process complexity and cost compared to the established fabrication technology of micro-opto-mechanical diamond devices. Here, we report on the direct comparison of both approaches and present first proof-of-concept planar-FCAE-prototypes for scanning probe applications.
20
Liu, Yan, Xiang Cheng, Tingting Zhang, Yu Xu, Weijia Cai et Fengtian Han. « Scanning Micromirror Calibration Method Based on PSO-LSSVM Algorithm Prediction ». Micromachines 15, no 12 (25 novembre 2024) : 1413. http://dx.doi.org/10.3390/mi15121413.
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Scanning micromirrors represent a crucial component in micro-opto-electro-mechanical systems (MOEMS), with a broad range of applications across diverse fields. However, in practical applications, several factors inherent to the fabrication process and the surrounding usage environment exert a considerable influence on the accuracy of measurements obtained with the micromirror. Therefore, it is essential to calibrate the scanning micromirror and its measurement system. This paper presents a novel scanning micromirror calibration method based on the prediction of a particle swarm optimization-least squares support vector machine (PSO-LSSVM). The objective is to establish a correspondence between the actual deflection angle of the micromirror and the output of the measurement system employing a regression algorithm, thereby enabling the prediction of the tilt angle of the micromirror. The decision factor (R2) for this model at the x-axis reaches a value of 0.9947.
21
Cachaneski-Lopes, João P., et Augusto Batagin-Neto. « Effects of Mechanical Deformation on the Opto-Electronic Responses, Reactivity, and Performance of Conjugated Polymers : A DFT Study ». Polymers 14, no 7 (26 mars 2022) : 1354. http://dx.doi.org/10.3390/polym14071354.
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The development of polymers for optoelectronic applications is an important research area; however, a deeper understanding of the effects induced by mechanical deformations on their intrinsic properties is needed to expand their applicability and improve their durability. Despite the number of recent studies on the mechanochemistry of organic materials, the basic knowledge and applicability of such concepts in these materials are far from those for their inorganic counterparts. To bring light to this, here we employ molecular modeling techniques to evaluate the effects of mechanical deformations on the structural, optoelectronic, and reactivity properties of traditional semiconducting polymers, such as polyaniline (PANI), polythiophene (PT), poly (p-phenylene vinylene) (PPV), and polypyrrole (PPy). For this purpose, density functional theory (DFT)-based calculations were conducted for the distinct systems at varied stretching levels in order to identify the influence of structural deformations on the electronic structure of the systems. In general, it is noticed that the elongation process leads to an increase in electronic gaps, hypsochromic effects in the optical absorption spectrum, and small changes in local reactivities. Such changes can influence the performance of polymer-based devices, allowing us to establish significant structure deformation response relationships.
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Borga, Piero, Francesca Milesi, Nicola Peserico, Chiara Groppi, Francesco Damin, Laura Sola, Paola Piedimonte et al. « Active Opto-Magnetic Biosensing with Silicon Microring Resonators ». Sensors 22, no 9 (25 avril 2022) : 3292. http://dx.doi.org/10.3390/s22093292.
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Integrated optical biosensors are gaining increasing attention for their exploitation in lab-on-chip platforms. The standard detection method is based on the measurement of the shift of some optical quantity induced by the immobilization of target molecules at the surface of an integrated optical element upon biomolecular recognition. However, this requires the acquisition of said quantity over the whole hybridization process, which can take hours, during which any external perturbation (e.g., temperature and mechanical instability) can seriously affect the measurement and contribute to a sizeable percentage of invalid tests. Here, we present a different assay concept, named Opto-Magnetic biosensing, allowing us to optically measure off-line (i.e., post hybridization) tiny variations of the effective refractive index seen by microring resonators upon immobilization of magnetic nanoparticles labelling target molecules. Bound magnetic nanoparticles are driven in oscillation by an external AC magnetic field and the corresponding modulation of the microring transfer function, due to the effective refractive index dependence on the position of the particles above the ring, is recorded using a lock-in technique. For a model system of DNA biomolecular recognition we reached a lowest detected concentration on the order of 10 pm, and data analysis shows an expected effective refractive index variation limit of detection of 7.5×10−9 RIU, in a measurement time of just a few seconds.
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Borga, Piero, Francesca Milesi, Nicola Peserico, Chiara Groppi, Francesco Damin, Laura Sola, Paola Piedimonte et al. « Active Opto-Magnetic Biosensing with Silicon Microring Resonators ». Sensors 22, no 9 (25 avril 2022) : 3292. http://dx.doi.org/10.3390/s22093292.
Texte intégralRésumé :
Integrated optical biosensors are gaining increasing attention for their exploitation in lab-on-chip platforms. The standard detection method is based on the measurement of the shift of some optical quantity induced by the immobilization of target molecules at the surface of an integrated optical element upon biomolecular recognition. However, this requires the acquisition of said quantity over the whole hybridization process, which can take hours, during which any external perturbation (e.g., temperature and mechanical instability) can seriously affect the measurement and contribute to a sizeable percentage of invalid tests. Here, we present a different assay concept, named Opto-Magnetic biosensing, allowing us to optically measure off-line (i.e., post hybridization) tiny variations of the effective refractive index seen by microring resonators upon immobilization of magnetic nanoparticles labelling target molecules. Bound magnetic nanoparticles are driven in oscillation by an external AC magnetic field and the corresponding modulation of the microring transfer function, due to the effective refractive index dependence on the position of the particles above the ring, is recorded using a lock-in technique. For a model system of DNA biomolecular recognition we reached a lowest detected concentration on the order of 10 pm, and data analysis shows an expected effective refractive index variation limit of detection of 7.5×10−9 RIU, in a measurement time of just a few seconds.
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Wu, Wen Hong, Kuo Cheng Huang et Shih Feng Tseng. « Multi-Sphere Mirror Design of YAG Laser Applied for Glass Substrate Cutting ». Advanced Materials Research 264-265 (juin 2011) : 1246–51. http://dx.doi.org/10.4028/www.scientific.net/amr.264-265.1246.
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A thermal fracture process applied to the brittle materials has become a foremost technology, and applied to cut the LCD glass substrate. One advantage of this process is that the cross-section of cut glass substrate will be smooth with low residual stress after thermal fracture processing. The multi-sphere mirror aims to repeatedly reflect the light energy within upper and lower mirror in order to enhance the laser beam absorption rate of glass under cutting. Moreover, with a proper design of multi-sphere mirror, the energy distribution of applied laser can provide an ideal thermal fracture condition to improve cutting speed of glass substrate. A novel reflective mirror with multi-sphere surface was developed and reported to transform the regular laser energy distribution toward the ideal one. Furthermore, the shape of multi-sphere mirror is optimized by Taguchi method so as to meet the surface requirement that can get the ideal energy distribution. This paper presents a series of simulation results and analysis results of multi-sphere mirror calculated by the TracePro opto-mechanical software.
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Babilotte, Philippe. « A Basic Complete Numerical Toolbox for Picosecond Ultrasonics ». Acoustics 1, no 1 (17 janvier 2019) : 137–55. http://dx.doi.org/10.3390/acoustics1010010.
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A complete numerical complete toolbox is proposed concerning the simulation of photo-induced propagative mechanical wave, and concerning the optical reflectometric measured response of the material, which is initially exposed to a first pump laser beam that photo-induces the acoustic wavefronts. The deformation field and its propagation into a bulk material are simulated. Based on this field expression, the complex transient reflectivity is given for a medium considered as homogeneous. The real part of this quantity permits afterwards to propose a numerical simulation of the transient reflectivity, which corresponds to the optical signal measured during experimental works. The frequency acoustic spectrum is simulated and successfully compared to the measured frequency spectrum. For the first time, numerical complete developments are explicitly proposed and fully-developed under the SciLab ® environment, related to the simulation of laser-induced picosecond acoustic wavefront photogenerated through an opto-acoustic transduction process (ultrasonics and pretersonics).
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Rai, R. S., K. T. Faber, S. Guruswamy et J. P. Hirth. « Transmission Electron Microscopy studies in deformed GaxIn1-xAs ». Proceedings, annual meeting, Electron Microscopy Society of America 45 (août 1987) : 320–21. http://dx.doi.org/10.1017/s042482010012641x.
Texte intégralRésumé :
The control of dislocation density during the growth of GaAs and related compounds is highly desirable for obtaining improved performance and reliability of opto-electronic devices. Doping of single crystal GaAs grown by the LEC process with Indium has been known to reduce the dislocation density significantly. Substitutional solid-solution strengthening of GaAs as an InAs, unit has been suggested to be responsible for reduction of dislocation density. To understand the mechanism involved in dislocation density reduction, deformation tests have been performed on [001] oriented Gax In1-xAs single crystals in the temperature range 700-1100°C and this paper reports some results of the TEM characterization of dislocations in these deformed single crystals.Specimens of GaAs and Ga0.99In0.01As For TEM observations were made by cutting thin slices in a desired orientation, followed by mechanical polishing and ion-milling. These specimens were examined in a JEOL JEM 200CX transmission electron microscope at 200KeV equipped with a double-tilt goniometer stage.
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Forel, Salome, Yamaldi Midiladji Bakary, Catherine Marichy, Han Li, Wim Wenseleers, Benjamin S. Flavel, Sofie Cambre et Cerdric Desroches. « (Invited) Advance in Single-Wall Carbon Nanotubes Filling ». ECS Meeting Abstracts MA2024-01, no 9 (9 août 2024) : 875. http://dx.doi.org/10.1149/ma2024-019875mtgabs.
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Single-wall carbon nanotubes (SWCNTs) are renowned for their outstanding charge carrier mobility, optical, thermal, and mechanical properties. Combining these characteristics with their nanometer-scale diameter renders them highly promising for developing (opto)-electronic devices, where the challenge lies in achieving miniaturization without compromising performance. In addition to their intrinsic characteristics, SWCNTs feature a hollow core that can be filled with various molecules1, resulting in unique one-dimensional hybrids that integrate the properties of the nanotube with those of the encapsulated molecule. This study emphasizes recent advancements, particularly the extensive chirality-sorting2 of these hybrids and a novel methodology utilizing vapor phase infiltration and tailored synthesis strategies to create new fillers. These approaches aim to enhance control over the filling process for finer tuning of the SWCNT doping level or their photosensitization/reactivity capabilities under visible light. References [1] S. Cambré et al. Small, 2021 17, 2102585 [2] S. Forel et al. Nanoscale, 2022, 14, 8385
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Shaloo, Masoud, Martin Schnall, Thomas Klein, Norbert Huber et Bernhard Reitinger. « A Review of Non-Destructive Testing (NDT) Techniques for Defect Detection : Application to Fusion Welding and Future Wire Arc Additive Manufacturing Processes ». Materials 15, no 10 (21 mai 2022) : 3697. http://dx.doi.org/10.3390/ma15103697.
Texte intégralRésumé :
In Wire and Arc Additive Manufacturing (WAAM) and fusion welding, various defects such as porosity, cracks, deformation and lack of fusion can occur during the fabrication process. These have a strong impact on the mechanical properties and can also lead to failure of the manufactured parts during service. These defects can be recognized using non-destructive testing (NDT) methods so that the examined workpiece is not harmed. This paper provides a comprehensive overview of various NDT techniques for WAAM and fusion welding, including laser-ultrasonic, acoustic emission with an airborne optical microphone, optical emission spectroscopy, laser-induced breakdown spectroscopy, laser opto-ultrasonic dual detection, thermography and also in-process defect detection via weld current monitoring with an oscilloscope. In addition, the novel research conducted, its operating principle and the equipment required to perform these techniques are presented. The minimum defect size that can be identified via NDT methods has been obtained from previous academic research or from tests carried out by companies. The use of these techniques in WAAM and fusion welding applications makes it possible to detect defects and to take a step towards the production of high-quality final components.
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Hanuhov, Tamara, Eric Asulin et Raz Gvishi. « Evaluation of opto-mechanical properties of UV-cured and thermally-cured sol-gel hybrids monoliths as a function of organic content and curing process ». Journal of Non-Crystalline Solids 471 (septembre 2017) : 301–11. http://dx.doi.org/10.1016/j.jnoncrysol.2017.05.043.
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Zhang, Shao Jun, Yue Ming Liu et Xiao Hong Huangfu. « Mechanism and Simulation of Bi-Layered Micro Optical Fiber Resonator ». Applied Mechanics and Materials 241-244 (décembre 2012) : 841–46. http://dx.doi.org/10.4028/www.scientific.net/amm.241-244.841.
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Micro-resonators could be fabricated directly on the optical fiber top by micro mechanical process. The micro optical fiber resonator has more great advantages comparing with the traditional optical excited micro silicon resonators, such as being optically positioned easily between the resonator and the optical fiber end. By this way, the optical excited light through the fiber core is thus put on the micro resonator accurately and then partially reflected by the Fabry-Perot interferometer formed between fiber top and resonator surface. The reflected light from F-P interferometer was sent to the opto-electric detector PIN to demodulate the detected parameter. A matched metal layer can be deposited atop of the resonator in order to increase the optical excitation efficiency. Firstly mechanism analysis of optical excited bi-layered resonator is given by fully considering Longitudinal thermal strain effect and Bi-coating effect, and then the typical theoretical models were setup including the resonating frequency and resonant amplitude, and temperature sensing feature was simulated by computer software. The simulation results indicated that the average frequency sensitivity of temperature sensing is about 29Hz/°C.
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LENG, M., E. HAEMMERLE, W. CHEN, M. HODGSON et W. GAO. « QUANTIFYING THE PERFORMANCE OF MULTIPLE-OUTPUT PIEZOELECTRIC OPTICAL SWITCHES ». International Journal of Modern Physics B 24, no 15n16 (30 juin 2010) : 2345–50. http://dx.doi.org/10.1142/s0217979210064903.
Texte intégralRésumé :
Optical switch prototypes are developed based on the new concept that the input fiber is directly moved by the deflection of a piezoelectric tube actuator. The piezoelectric tube actuators used in the switch prototypes are manufactured by an electrophoretic deposition process. The tubes are low cost and compact in size with an inner diameter of less than 1mm. They have a deflection of 65 µm which is adequate to actuate the input fiber for switching. A number of multimode 1×2 fiber optical switch prototypes have previously been built. To develop the new 1×4 optical switch, a new output fiber alignment device was fabricated. The conductive coating on the piezoelectric tube actuator was sectored into four. Also, the power supply unit was redesigned in order to provide high voltage for the four-sectored tube. The success in the 1×4 prototype development proves that the new multiple-output piezoelectric switching concept is feasible. The concept demonstrates an advantage over some other opto-mechanical switches which need to be cascaded to achieve a multiple-output configuration.
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Sharma, Varun P., Tapas Ganguli et Rahul Shukla. « Computational analysis of vertical comb-drive microactuator with extended mirror for manipulation of light ». Journal of Vacuum Science & ; Technology B 40, no 6 (décembre 2022) : 063001. http://dx.doi.org/10.1116/6.0002190.
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Squeeze film damping is a dominant mechanism to examine the losses in the micro-opto-electro-mechanical systems. It plays an important role in understanding the dynamic performance of vertical-comb drive (VCD) microactuator. In the present paper, finite element method is used to estimate the Q factor and damping ratio at varying ambient pressures ranging from atmospheric (105 Pa) to vacuum (0.1 Pa) in COMSOL Multiphysics. The effect of ambient pressure on dynamic performance of the VCD is discussed in detail. Based on the applications, two different VCDs (VCD-L and VCD-SR) with extended micromirrors have been proposed in the current study for the manipulation of light. VCD-L having lower eigen frequency of 670 Hz can be used in laser and biomedical applications. VCD-SR with higher eigen frequency nearly 90 kHz has the potential use in a synchrotron radiation source. In addition, a parametric study is done to understand the performance of VCD for varying process parameters such as variable offset length among the comb fingers, spring dimensions, and orientation of single crystal silicon. For spring design, the von-Mises stress theory is preferred over maximum shear stress theory.
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Hiller, Jonathan, Joni Mici et Hod Lipson. « Layered assemblers for scalable parallel integration ». Journal of The Royal Society Interface 17, no 171 (octobre 2020) : 20200543. http://dx.doi.org/10.1098/rsif.2020.0543.
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Many complex natural and artificial systems are composed of large numbers of elementary building blocks, such as organisms made of many biological cells or processors made of many electronic transistors. This modular substrate is essential to the evolution of biological and technological complexity, but has been difficult to replicate for mechanical systems. This study seeks to answer if layered assembly can engender exponential gains in the speed and efficacy of block or cell-based manufacturing processes. A key challenge is how to deterministically assemble large numbers of small building blocks in a scalable manner. Here, we describe two new layered assembly principles that allow assembly faster than linear time, integrating n modules in O( n 2/3 ) and O( n 1/3 ) time: one process uses a novel opto-capillary effect to selectively deposit entire layers of building blocks at a time, and a second process jets building block rows in rapid succession. We demonstrate the fabrication of multi-component structures out of up to 20 000 millimetre scale spherical building blocks in 3 h. While these building blocks and structures are still simple, we suggest that scalable layered assembly approaches, combined with a growing repertoire of standardized passive and active building blocks could help bridge the meso-scale assembly gap, and open the door to the fabrication of increasingly complex, adaptive and recyclable systems.
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Duma, Virgil-Florin, et Maria-Alexandra Duma. « Optomechanical Analysis and Design of Polygon Mirror-Based Laser Scanners ». Applied Sciences 12, no 11 (31 mai 2022) : 5592. http://dx.doi.org/10.3390/app12115592.
Texte intégralRésumé :
Polygon Mirror (PM)-based scanning heads are one of the fastest and most versatile optomechanical laser scanners. The aim of this work is to develop a multi-parameter opto-mechanical analysis of PMs, from which to extract rules-of-thumbs for the design of such systems. The characteristic functions and parameters of PMs scanning heads are deduced and studied, considering their constructive and functional parameters. Optical aspects related to the kinematics of emergent laser beams (and of corresponding laser spots on a scanned plane or objective lens) are investigated. The PM analysis (which implies a larger number of parameters) is confronted with the corresponding, but less complex aspects of Galvanometer Scanners (GSs). The issue of the non-linearity of the scanning functions of both PMs and GSs (and, consequently, of their variable scanning velocities) is approached, as well as characteristic angles, the angular and linear Field-of-View (FOV), and the duty cycle. A device with two supplemental mirrors is proposed and designed to increase the distance between the GS or PM and the scanned plane or lens to linearize the scanning function (and thus to achieve an approximately constant scanning velocity). These optical aspects are completed with Finite Element Analyses (FEA) of fast rotational PMs, to assess their structural integrity issues. The study is concluded with an optomechanical design scheme of PM-based scanning heads, which unites optical and mechanical aspects—to allow for a more comprehensive approach of possible issues of such scanners. Such a scheme can be applied to other types of optomechanical scanners, with mirrors or refractive elements, as well.
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Tian, Jinbi, Zexu Lin, Zhiyuan Chen, Sofian N. Obaid, Igor R. Efimov et Luyao Lu. « Stretchable and Transparent Metal Nanowire Microelectrodes for Simultaneous Electrophysiology and Optogenetics Applications ». Photonics 8, no 6 (15 juin 2021) : 220. http://dx.doi.org/10.3390/photonics8060220.
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Recently developed optically transparent microelectrode technology provides a promising approach for simultaneous high-resolution electrical and optical biointerfacing with tissues in vivo and in vitro. A critically unmet need is designing high-performance stretchable platforms for conformal biointerfacing with mechanically active organs. Here, we report silver nanowire (Ag NW) stretchable transparent microelectrodes and interconnects that exhibit excellent electrical and electrochemical performance, high optical transparency, superior mechanical robustness and durability by a simple selective-patterning process. The fabrication method allows the direct integration of Ag NW networks on elastomeric substrates. The resulting Ag NW interface exhibits a low sheet resistance (Rsh) of 1.52–4.35 Ω sq−1, an advantageous normalized electrochemical impedance of 3.78–6.04 Ω cm2, a high optical transparency of 61.3–80.5% at 550 nm and a stretchability of 40%. The microelectrode arrays (MEAs) fabricated with this approach exhibit uniform electrochemical performance across all channels. Studies on mice demonstrate that both pristine and stretched Ag NW microelectrodes can achieve high-fidelity electrophysiological monitoring of cardiac activity with/without co-localized optogenetic pacing. Together, these results pave the way for developing stretchable and transparent metal nanowire networks for high-resolution opto-electric biointerfacing with mechanically active organs, such as the heart.
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Hanss, Alexander, et Gordon Elger. « Residual free solder process for fluxless solder pastes ». Soldering & ; Surface Mount Technology 30, no 2 (3 avril 2018) : 118–28. http://dx.doi.org/10.1108/ssmt-10-2017-0030.
Texte intégralRésumé :
Purpose For soldering, flux is essential because it enables the wetting of the molten solder. Fluxless soldering, i.e. residue-free soldering with the aid of gaseous activators, has been known for many years, but is only well established in the field of opto- and microwave electronics where the solder is applied as preform. In high-volume SMD applications where solder paste is printed, this technology is rarely used until now. The reducing effect of a gaseous activator like formic acid vapor on certain solder alloys is known in practice. However, the corresponding reactions which occur under soldering conditions in nitrogen atmosphere have so far not been systematically investigated for different solder alloys. This study aims to analyze the different chemical reaction channels which occur on the surface of different solders, i.e. catalytical dissociation of formic acid on the pure or oxidized metal surface and the formation and evaporation of metal formates. Based on this analysis, a residue-free solder process under formic acid is developed for solder paste applications. Design/methodology/approach In this paper, different solder alloys (SnAgCu, SnPb, BiSn, In) were analyzed with thermal gravimetric analysis (TGA) under formic acid flow. Details on mass change depending on the soldering temperature are presented. Activation temperatures are estimated and correlated to the soldering processes. Based on the analysis, fluxless solder pastes and suitable soldering processes are developed and presented. Major paste properties such as printability are compared to a commercial flux solder paste. High-power flip chip LEDs which can be assembled directly on a printed circuit board are used to demonstrate the fluxless soldering. Likewise, the soldering results of standard paste and fluxless paste systems after a reflow process are evaluated and compared. Findings The experimental results show that TGA is an efficient way to gain deeper understanding of the redox processes which occur under formic acid activation, i.e. the formation of metal formates and their evaporation and dissociation. It is possible to solder residue-free not only with preforms but also with a fluxless solder paste. The resulting solder joints have the same quality as those for standard solder paste in terms of voids detected by X-ray and mechanical shear strength. Originality/value In the fluxless soldering process, the reduction of oxide layers, and therefore the wetting of the solder spheres, is enabled by gaseous formic acid. After the soldering process, no cleaning process is necessary because no corrosive residues are left on the circuit boards and components. Therefore, soldering using solder paste without aggressive chemical ingredients has a high market potential. Expensive preforms could be replaced by paste dispensing or paste printing.
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Özuğur Uysal, Bengü, Şeyma Nayır, Melike Açba, Betül Çıtır, Sümeyye Durmaz, Şevval Koçoğlu, Ekrem Yıldız et Önder Pekcan. « 2D Materials (WS2, MoS2, MoSe2) Enhanced Polyacrylamide Gels for Multifunctional Applications ». Gels 8, no 8 (25 juillet 2022) : 465. http://dx.doi.org/10.3390/gels8080465.
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Multifunctional polymer composite gels have attracted attention because of their high thermal stability, conductivity, mechanical properties, and fast optical response. To enable the simultaneous incorporation of all these different functions into composite gels, the best doping material alternatives are two-dimensional (2D) materials, especially transition metal dichalcogenides (TMD), which have been used in so many applications recently, such as energy storage units, opto-electronic devices and catalysis. They have the capacity to regulate optical, electronic and mechanical properties of basic molecular hydrogels when incorporated into them. In this study, 2D materials (WS2, MoS2 and MoSe2)-doped polyacrylamide (PAAm) gels were prepared via the free radical crosslinking copolymerization technique at room temperature. The gelation process and amount of the gels were investigated depending on the optical properties and band gap energies. Band gap energies of composite gels containing different amounts of TMD were calculated and found to be in the range of 2.48–2.84 eV, which is the characteristic band gap energy range of promising semiconductors. Our results revealed that the microgel growth mechanism and gel point of PAAm composite incorporated with 2D materials can be significantly tailored by the amount of 2D materials. Furthermore, tunable band gap energies of these composite gels are crucial for many applications such as biosensors, cartilage repair, drug delivery, tissue regeneration, wound dressing. Therefore, our study will contribute to the understanding of the correlation between the optical and electronic properties of such composite gels and will help to increase the usage areas so as to obtain multifunctional composite gels.
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Komarovsky, N. Yu, E. V. Molodtsova, A. G. Belov, M. B. Grishechkin, R. Yu Kozlov, S. S. Kormilitsina, E. O. Zhuravlev et M. S. Nestyurkin. « Study of indium antimonide single crystals obtained by the modernized Chokhralsky method in several crystallographic directions ». Industrial laboratory. Diagnostics of materials 89, no 8 (24 août 2023) : 38–46. http://dx.doi.org/10.26896/1028-6861-2023-89-8-38-46.
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Single-crystal indium antimonide InSb is an indispensable material in such branches of solid-state electronics as opto- and nanoelectronics. In turn, the dislocation density and the character of their distribution, which directly depend on the technological parameters of the growth process, considerably determine the physical and mechanical properties of the material. We present the results of studying InSb single crystals obtained by the modernized Czochralski method in the crystallographic directions [100], [111], and [112]. The effect of growth conditions (axial and radial temperature gradients at the crystallization front) on the dislocation structure of InSb plates and the structural properties of the plates were analyzed. Using the method of selective etching it was shown that the number of etching pits on the wafers with different orientations differs by approximately an order of magnitude (103 cm–2 for plane (111) and 102 cm–2 for (100)). Number of etch pits for the (100) plane is commensurate with their number in crystals grown in the [112] and [100] directions. Probably, the maximum dislocation density in InSb single crystals can be considered as a material constant, and the increased strength of single crystals grown at lower axial gradients at the crystallization front is related to the formation of a characteristic ensemble of point defects along the dislocation line through diffusion. It is shown that InSb wafers [112] (100) exhibit the best physical and mechanical properties. The results obtained can be used in the manufacture of structures for photodetectors, in particular, in plate processing (cutting, grinding and polishing) to optimize technological processes.
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Vlasenko, O. I. « INDUCED RESTRUCTURING OF THE CRYSTAL STRUCTURE AND ACOUSTIC RESPONSE IN SEMICONDUCTORS BASED ON CADMIUM TELLURIDE FOR USE IN OPTOELECTRONICS AND TOPICAL AREAS OF SEMICONDUCTOR TECHNOLOGY (REVIEW) ». Optoelektronìka ta napìvprovìdnikova tehnìka 57 (30 décembre 2022) : 43–70. http://dx.doi.org/10.15407/iopt.2022.57.043.
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The reliability and competitiveness of modern semiconductor electronic technology are determined by the level of existing technologies. These requirements set the task of increasing the efficiency of methods for obtaining and post-growth processing of semiconductor materials and structures, research and control of their properties at all stages of manufacturing and operation of products. The question of the quality and maximum reliability of a wide range of various structures and devices for multipurpose purposes, in particular, opto, photoelectronics, sensors, etc., and sometimes the need to use it at the most achievable physical and technical parameters, or in extreme conditions, is becoming increasingly important. The solution to these problems is based on a comprehensive study of the processes of defect formation, failure and destruction of semiconductor structures and devices based on them. In modern conditions, for this purpose, in particular, the method of acoustic emission (AE) is used, based on the registration, theoretical processing of acoustic pulses that arise as a result of the formation, local changes and destruction of the structure of the material under external load. The most widespread practical application in various branches of semiconductor electronics have found materials based on CdTe, given, in particular, basic data on methods and sources of acoustic response induced by external influences. This method makes it possible to obtain information about the state of a solid in the process of deformation, in particular, to detect in a non-destructive way the presence or appearance of dislocations and microcracks. The AE process allows you to determine the mechanical stresses and deformations at which there is a transition from elastic to plastic deformation (yield strength) of the crystal and subsequent destruction. AE, which occurs during the deformation of a solid in local areas, in particular, under mechanical loads, ultrasound, laser irradiation, radiation exposure and in other cases, may have a thermomechanical nature and occur as a result of heterogeneous heating, for example, during the flow of electric current through a heterogeneous medium. Mechanical, thermomechanical or thermobaric stresses appear in crystals under appropriate phase transformations, in particular, during melting during laser irradiation. Thus, AE is an effective non-destructive method for identifying the initial stages of degradation and subsequent destruction of semiconductor materials, structures and devices under various external influences. The main purpose of this review is to distribute AE from macro objects (in technical diagnostics and control of industrial and domestic structures) to micro-objects for materials and structures of low-dimensional electronics, to expand the scientifically conscious application of AE in experimental and practical work in various semiconductor materials and structures on the example of CdTe-based semiconductors (wide- and narrow-band).
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Levchenko, V., I. Shulga, А. Romanyuk et L. Bezverkha. « USE OF REMOTE GEOINFORMATION TECHNOLOGIES FOR FOREST PATHOLOGY MONITORING IN THE ZHYTOMYR POLISSYA ». Innovative Solution in Modern Science 2, no 38 (30 mars 2020) : 20. http://dx.doi.org/10.26886/2414-634x.2(38)2020.3.
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Topical issues of remote assessment of the forest pathological condition of forests are substantiated, in particular, it is emphasized that today this type of decryption is the least developed link in the section of forest decoding. This is due to the unstable manifestation and diagnosis on the materials of aeronautical surveys of signs of deciphering trees and plantations of varying degrees of attenuation and drying. Forest decoding of aerospace imagery materials today is the process of recognizing aerial objects depicted on aerospace images and establishing their quantitative and qualitative characteristics. The subject of the work is the fundamental aspects of forest decoding, which in turn can be visual (eye, analytical), measuring, automatic (machine), as well as complex-analytical or automated (interactive). For all types of visual decoding of the investigated forest objects, as a rule, characterize, on the basis of decryption signs, its image on an aerial photo or space picture (on paper or computer screen) with the naked eye or by means of magnifying or stereoscopic devices. Therefore, methodological correctness and clarity in deciphering satellite images of forest arrays obtained through satellite communication channels is quite important today, using satellite and internet technologies. The purpose of the study is to study and systematize materials for deciphering geoinformation images of forests that were obtained by satellite sounding of forests in Ukraine as a whole, and in the Zhytomyr region in particular. The main methods of carrying out the works are the computational-analytical on the collection and processing of the results of space images of satellite sounding of forests located in the territory of Zhytomyr region. In addition, it should be noted that remote satellite sensing of forests enables, with the correct methodological decryption of space images, not only to monitor, but also to make a prediction of the spread of harmful organisms in the forests of Zhytomyr region. The main methods of carrying out the works are the computational-analytical on the collection and processing of the results of space images of satellite sounding of forests located in the territory of Zhytomyr region. In addition, it should be noted that remote satellite sensing of forests enables, with the correct methodological decryption of space images, not only to monitor, but also to make a prediction of the spread of harmful organisms in the forests of Zhytomyr region. According to the results of the work, it is established that the information from the aerospace image is read and analyzed by means of visual and logical devices of the decoder. Therefore, analytical decryption, and especially with the use of certified computer software, allows not only a high-quality reading of space images of forest covered areas of Zhytomyr region, but also to make a long-term forecast for the spread and spread of pests and diseases of the forest in a certain area. The scope of the research results are forestry enterprises of the Zhytomyr Regional Forestry and Hunting Directorate, Ecological and Naturalistic Centers, State environmental inspections including in the Zhytomyr region for space monitoring of the state of forest ecosystems, as well as conducting forestry and nature activities forest of Zhytomyr Polesie. The conclusions of the research are that in Zhytomyr Polissya, when measuring decryption, all or some of the parameters and characteristics of the decrypted objects are measured in pictures using mechanical, opto-mechanical, opto-electronic and other measuring instruments, devices, devices and systems. In analytical-measuring decryption, a visual-logical analysis of the image is combined with the measurement of different parameters of the decrypted objects. Automatic decryption is based on the recognition of spectral and morphometric characteristics of decrypted objects, their quantitative and qualitative indicators. In this case, the decryption process is performed using image processing equipment. The role of the individual is to create a system, define a specific task and process the captured information with the help of appropriate programs, and to maintain the normal functioning of the system. Automated (interactive) decryption combines elements of analytic-measuring, performed by the decryptor-operator on the image on the computer screen, with automatic decryption. In this case, the collected information is analyzed and processed using technical means of image processing with the active participation of the decoder. Depending on the location, the decryption can be field, camera (laboratory), aerial or combined. Field decryption is carried out directly on the ground by comparing the image on aerial or space images with nature. The field decryption method is the simplest and most accurate, but it takes a lot of time and labor. Cameral decryption is carried out in the laboratory, while reducing the cost of engineering staff and workers, there is an acceleration of work and a significant reduction in their cost. Camera decryption is always done with the help of additional cartographic, regulatory and other stock materials. Aero-visual decryption is performed by comparing images of identified objects in aerial or space imagery with terrain when flying on planes or helicopters. The analysis of the informative content of the shooting materials shows that their practical application is possible, as a rule, on the basis of a rational combination of methods of terrestrial and remote observations.Keywords: remote evaluation, forest pathological condition, aerial photos, aerial photos, remote satellite sounding of forests, signs of decryption, space monitoring of forests in Zhytomyr region.
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Franke, Jörg, Jochen Zeitler et Thomas Reitberger. « A novel engineering process for spatial opto-mechatronic applications ». CIRP Annals 65, no 1 (2016) : 153–56. http://dx.doi.org/10.1016/j.cirp.2016.04.091.
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Huang, Jiahan, Chengbin Jiang, Guanghui Li, Qinghua Lu et Haichu Chen. « Design and Analysis of a Light-Operated Microgripper Using an Opto-Electrostatic Repulsive Combined Actuator ». Micromachines 12, no 9 (27 août 2021) : 1026. http://dx.doi.org/10.3390/mi12091026.
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The microgripper plays a critical role in micromanipulation systems; however, the handling accuracy of traditional driving microgrippers suffers from external vibration due to requiring connecting wires for an external power supply. By contrast, light driving has many advantages of remote non-contact manipulation, wireless energy transfer and no induced electromagnetic noise. In this study, an opto-electrostatic repulsive combined driving mechanism was proposed, and then a novel light-operated microgripper that used an opto-electrostatic repulsive actuator was designed and simulated. The static performance of the light-operated microgripper was investigated via simulation and numeric calculation results. The overall size of the microgripper was 1.3 mm × 0.7 mm × 1.027 mm, and the micro-objects ranging from 0 to 1000 μm in size could be manipulated and held using light. The proposed microgripper had many outstanding characteristics, such as a larger stroke, high response speed, remote non-contact manipulation, easy to integrate with an integrated circuit (IC) process and free from external interference. In addition, the dynamic control experiments of the photo-induced voltage of the PbLaZrTi (PLZT) ceramic were carried out, which shows that a stable electrical field could be obtained using the effective control methods that were developed.
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Jia, Yaoyao, Yan Gong, Arthur Weber, Wen Li et Maysam Ghovanloo. « A mm-Sized Free-Floating Wireless Implantable Opto-Electro Stimulation Device ». Micromachines 11, no 6 (25 juin 2020) : 621. http://dx.doi.org/10.3390/mi11060621.
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Towards a distributed neural interface, consisting of multiple miniaturized implants, for interfacing with large-scale neuronal ensembles over large brain areas, this paper presents a mm-sized free-floating wirelessly-powered implantable opto-electro stimulation (FF-WIOS2) device equipped with 16-ch optical and 4-ch electrical stimulation for reconfigurable neuromodulation. The FF-WIOS2 is wirelessly powered and controlled through a 3-coil inductive link at 60 MHz. The FF-WIOS2 receives stimulation parameters via on-off keying (OOK) while sending its rectified voltage information to an external headstage for closed-loop power control (CLPC) via load-shift-keying (LSK). The FF-WIOS2 system-on-chip (SoC), fabricated in a 0.35-µm standard CMOS process, employs switched-capacitor-based stimulation (SCS) architecture to provide large instantaneous current needed for surpassing the optical stimulation threshold. The SCS charger charges an off-chip capacitor up to 5 V at 37% efficiency. At the onset of stimulation, the capacitor delivers charge with peak current in 1.7–12 mA range to a micro-LED (µLED) array for optical stimulation or 100–700 μA range to a micro-electrode array (MEA) for biphasic electrical stimulation. Active and passive charge balancing circuits are activated in electrical stimulation mode to ensure stimulation safety. In vivo experiments conducted on three anesthetized rats verified the efficacy of the two stimulation mechanisms. The proposed FF-WIOS2 is potentially a reconfigurable tool for performing untethered neuromodulation.
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Rutelli, G., et D. Cuppini. « Development of Wear Sensor for Tool Management System ». Journal of Engineering Materials and Technology 110, no 1 (1 janvier 1988) : 59–62. http://dx.doi.org/10.1115/1.3226011.
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In automatic metalworking systems, in-process tool-life monitoring and quality control of the parts produced play a crucial role. This paper is on the architecture and performance of an opto-electronic sensor designed for automatic tool-wear monitoring in Computer Numerical Controlled (CNC) lathe applications. Tool wear is sensed by detecting the wear land image, which is captured by an analogic camera, digitized and processed using a computer system. The computer system, linked to the lathe control module, implements a real-time procedure supporting an optimal tool replacement strategy.
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Yuan, Zhipeng, Liheng Chen, Hasiaoqier Han, Limin Ren, Shuai Liu et Renxin Wang. « Optimal design of thermal control system for space optical remote sensor based on NSGA-II and opto-mechanical-thermal integration analysis ». Case Studies in Thermal Engineering 43 (mars 2023) : 102813. http://dx.doi.org/10.1016/j.csite.2023.102813.
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Gusarova, N. F. « Opto-Electronic Testing of Movable Operating Elements of a Knitting Machine in the Process of Manufacturing Jersey Fabrics ». Russian Journal of Nondestructive Testing 39, no 2 (février 2003) : 136–44. http://dx.doi.org/10.1023/b:runt.0000008390.84939.dc.
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Sohail, Amjad, Rizwan Ahmed, Jia-Xin Peng, Tariq Munir, Aamir Shahzad, S. K. Singh et Marcos César de Oliveira. « Controllable Fano-type optical response and four-wave mixing via magnetoelastic coupling in an opto-magnomechanical system ». Journal of Applied Physics 133, no 15 (21 avril 2023) : 154401. http://dx.doi.org/10.1063/5.0133156.
Texte intégralRésumé :
We analytically investigate the Fano-type optical response and the four-wave mixing (FWM) process by exploiting the magnetoelasticity of a ferromagnetic material. The deformation of the ferromagnetic material plays the role of mechanical displacement, which is simultaneously coupled to both optical and magnon modes. We report that the magnetostrictively induced displacement leads to realization of Fano profiles in the output field and is effectively well-tuned through adjusting the system parameters, such as effective magnomechanical coupling, magnon detuning, and cavity detuning. It is found that the magnetoelastic interaction also gives rise to the FWM phenomenon. The number of the FWM signals mainly depends upon the effective magnomechanical coupling and the magnon detuning. Moreover, the FWM spectrum exhibits suppressive behavior upon increasing (decreasing) the magnon (cavity) decay rate. The present scheme will open new perspectives in highly sensitive detection and quantum information processing.
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Hu, D., H. Mei et R. Kovacevic. « Improving solid freeform fabrication by laser-based additive manufacturing ». Proceedings of the Institution of Mechanical Engineers, Part B : Journal of Engineering Manufacture 216, no 9 (1 septembre 2002) : 1253–64. http://dx.doi.org/10.1243/095440502760291808.
Texte intégralRésumé :
Solid freeform fabrication (SFF) methods for metal part building, such as three-dimensional laser cladding, are generally less stable and less repeatable than other rapid prototyping methods. A large number of parameters govern the three-dimensional laser cladding process. These parameters are sensitive to the environmental variations, and they also influence each other. This paper introduces the research work in Research Center for Advanced Manufacturing (RCAM) to improve the performance of its developed three-dimensional laser cladding process: laser-based additive manufacturing (LBAM). Metal powder delivery real-time sensing is studied to achieve a further controllable powder delivery that is the key technology to build a composite material or alloy with a functionally gradient distribution. An opto-electronic sensor is designed to sense the powder delivery rate in real time. The experimental results show that the sensor's output voltage has a good linear relationship with the powder delivery rate. A closed-loop control system is also built for heat input control in the LBAM process, based on infrared image sensing. A camera with a high frame rate (up to 800frame/s) is installed coaxially to the top of the laser—nozzle set-up. A full view of the infrared images of the molten pool can be acquired with a short nozzle—substrate distance in different scanning directions, eliminating the image noise from the metal powder. The closed-loop control results show a great improvement in the geometrical accuracy of the built feature.
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Li, Tzu-Chien, Chia-Wen Chang, Chia-Chun Tai, Jyh-Jier Ho, Tung-Po Hsieh, Yung-Tsung Liu et Tsung-Lin Lu. « Optoelectronic Effects of Copper–Indium–Gallium–Sulfur (CIGS2)-Solar Cells Prepared by Three-Stage Co-Evaporation Process Technology ». Micromachines 14, no 9 (31 août 2023) : 1709. http://dx.doi.org/10.3390/mi14091709.
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In this paper, the performance of Cu-(In,Ga)-S2 (CIGS2) solar cells with adjusting composite [Cu]/([Ga] + [In]) (CGI)-ratio absorber was explored and compared through an improved three-stage co-evaporation technique. For co-evaporating CIGS2 absorber as a less toxic alternative to Cd-containing film, we analyzed the effect of the CGI-ratio stoichiometry and crystallinity, and explored its opto-electric sensing characteristic of individual solar cell. The results of this research signified the potential of high-performance CIGS2-absorption solar cells for photovoltaic (PV)-module industrial applications. For the optimal CIGS2-absorption film (CGI = 0.95), the Raman main-phase signal (A1) falls at 291 cm−1, which was excited by the 532 nm line of Ar+-laser. Using photo-luminescence (PL) spectroscopy, the corresponding main-peak bandgaps measured was 1.59 eV at the same CGI-ratio film. Meanwhile, the best conversion efficiency (η = 3.212%) and the average external quantum efficiency (EQE = 51.1% in the visible-wavelength region) of photo-electric properties were achieved for the developed CIGS2-solar cells (CGI = 0.95). The discoveries of this CIGS2-absorption PV research provided a new scientific understanding of solar cells. Moreover, this research undeniably contributes to a major advancement towards practical PV-module applications and can help more to build an eco-friendly community.
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Mescheder, Ulrich, Michael Lootze et Khaled Aljasem. « Evaluation and Optimization of a MOEMS Active Focusing Device ». Micromachines 12, no 2 (9 février 2021) : 172. http://dx.doi.org/10.3390/mi12020172.
Texte intégralRésumé :
In this paper we present a detailed evaluation of a micro-opto-electromechanical system (MOEMS) for active focusing which is realized using an electrostatically deformed thin silicon membrane. The evaluation is done using finite element methods and experimental characterization of the device behavior. The devices are realized in silicon on insulator technology. The influence of internal stress especially resulting from the high compressive buried oxide (BOX) layer is evaluated. Additionally, the effect of stress gradients in the crystalline device layer and of high reflective coatings such as aluminum is discussed. The influence of variations of some important process steps on the device performance is quantified. Finally, practical properties such as focal length control, long-term stability, hysteresis and dynamical response are presented and evaluated. The evaluation proves that the proposed membrane focusing device is suitable for high performance imaging (wavefront errors between λ/5–λ/10) with a large aperture (5 mm).