Compact infrared cryogenic wafer-level camera: design and experimental validation

International audienceWe present a compact infrared cryogenic multichannel camera with a wide field of view equal to 120 degrees. By merging the optics with the detector, the concept is compatible with both cryogenic constraints and wafer-level fabrication. The design strategy of such a camera is described, as well as its fabrication and integration process. Its characterization has been carried out in terms of the modulation transfer function and the noise equivalent temperature difference (NETD). The optical system is limited by the diffraction. By cooling the optics, we achieve a very low NETD equal to 15 mK compared with traditional infrared cameras. A postprocessing algorithm that aims at reconstructing a well-sampled image from the set of undersampled raw subimages produced by the camera is proposed and validated on experimental images. (C) 2012 Optical Society of Americ

Compact infrared pinhole fisheye for wide field applications

International audienceThe performances of a compact infrared optical system using advanced pinhole optics for wide field applications are given. This concept is adapted from the classical Tisse design in order to fit with infrared issues. Despite a low light gathering efficiency and a low resolution in comparison with classical lenses, pinhole imagery provides a long depth of field and a wide angular field of view. Moreover, by using a simple lens that compresses the field of view, the angular acceptance of this pinhole camera can be drastically widened to a value around 180{\textdegree}. This infrared compact system is named pinhole fisheye since it is based on the field lens of a classical fisheye system

Highly efficient and stable Ru/K-OMS-2 catalyst for NO oxidation

The influence of addition of a series of non noble and noble metals to a manganese oxide octahedral molecular sieve (OMS) with a cryptomelane structure (K-OMS-2) has been studied for NO oxidation in view of fast selective catalytic reduction applications. Fe, Cu, Zn, Pt, Pd, Ru and Ag were selected as dopant metals with a metal loading around 2 wt.%. The catalysts were characterized in detail by ICP-OES, N2 adsorption/desorption at 77 K, XRD, H2-TPR and HR-TEM. The highest NO conversion was obtained for a K-OMS-2 catalyst modified with ruthenium, showing a reaction rate up to 5.3 μmol g−1 s−1 at 584 K. A markedly higher catalyst reducibility upon incorporation of ruthenium can be proposed as an underlying reason for the enhanced catalytic performance.Se ha estudiado la influencia de la adición de una serie de metales nobles y no nobles a un tamiz molecular octaédrico (OMS) de óxido de manganeso con estructura de criptomelano (K-OMS-2) para la oxidación de NO con vistas a aplicaciones de reducción catalítica selectiva rápida. Se seleccionaron Fe, Cu, Zn, Pt, Pd, Ru y Ag como metales dopantes con una carga de metal de alrededor del 2 % en peso. Los catalizadores se caracterizaron en detalle por ICP-OES, adsorción/desorción de N 2 a 77 K, XRD, H 2 -TPR y HR-TEM. La mayor conversión de NO se obtuvo para un catalizador K-OMS-2 modificado con rutenio , mostrando una velocidad de reacción de hasta 5,3 μmol g - 1 s - 1 a 584 K. Se puede proponer una reducibilidad del catalizador marcadamente más alta tras la incorporación de rutenio como una razón subyacente para el rendimiento catalítico mejorado

Manganese oxide-based catalysts for toluene oxidation

Four different catalysts based on manganese oxide were prepared: a perovskite (LaMnO3), via sol-gel method; Mn2O3, rapid method and an Octahedral Molecular Sieve (OMS-2) by two different preparation methods, via solid state (OMSs) and hydrothermal method (OMSh). The physicochemical properties of these catalysts were characterized by X-ray diffraction (XRD), N2 adsorption–desorption at −196 °C, thermogravimetric and differential thermal analysis (TGA/DTA), inductively coupled plasma optical emission spectroscopy (ICP-OES) and temperature-programmed reduction with hydrogen (H2-TPR). Their catalytic performances were evaluated in the catalytic oxidation of toluene. Three consecutive catalytic cycles were performed for each catalyst in order to reach steady state performances. In order to assess the stability of the catalysts under reaction conditions, the catalytic performances were studied upon long term experiments running for 24 h at 25% of toluene conversion. For comparison purposes, the catalytic activity of the present manganese oxide catalysts was compared with that of typical industrial catalysts such as a commercial Pd/Al2O3 catalyst containing 0.78% Pd. The crystalline features detected in the XRD patterns, are well-consistent with the formation of the desired structures. Based on their specific surface area and their low-temperature reducibility, the catalysts were ranked as follows: OMSs > Mn2O3 > OMSh > LaMnO3. This trend was in good agreement with the performances observed in the catalytic removal of toluene. A kinetic model was proposed and a good agreement was obtained upon fitting with the experimental data.Se prepararon cuatro catalizadores diferentes a base de óxido de manganeso : una perovskita (LaMnO 3 ), por el método sol-gel; Mn 2 O 3 , método rápido y Tamiz Molecular Octaédrico (OMS-2) por dos métodos de preparación diferentes, vía estado sólido (OMS s ) e hidrotermal (OMS h ). Las propiedades fisicoquímicas de estos catalizadores se caracterizaron por difracción de rayos X (XRD), adsorción-desorción de N 2 a −196 °C, análisis termogravimétrico y térmico diferencial (TGA/DTA), espectroscopia de emisión óptica de plasma acoplado inductivamente (ICP-OES) y reducción a temperatura programada con hidrógeno (H 2-TPR). Sus actuaciones catalíticas se evaluaron en la oxidación catalítica de tolueno. Se realizaron tres ciclos catalíticos consecutivos para cada catalizador con el fin de alcanzar rendimientos de estado estable. Para evaluar la estabilidad de los catalizadores en las condiciones de reacción, se estudiaron los rendimientos catalíticos en experimentos a largo plazo durante 24 h al 25 % de conversión de tolueno. Con fines comparativos, la actividad catalítica de los presentes catalizadores de óxido de manganeso se comparó con la de los catalizadores industriales típicos, como el Pd/Al 2 O 3 comercial.catalizador que contiene 0,78% Pd. Las características cristalinas detectadas en los patrones XRD son consistentes con la formación de las estructuras deseadas. Según su área de superficie específica y su reducibilidad a baja temperatura, los catalizadores se clasificaron de la siguiente manera: OMS s > Mn 2 O 3 > OMS h > LaMnO 3 . Esta tendencia estaba en buen acuerdo con los rendimientos observados en la eliminación catalítica de tolueno. Se propuso un modelo cinético y se obtuvo un buen acuerdo al ajustar con los datos experimentales

Head-to-head intra-individual comparison of biodistribution and tumor uptake of 68Ga-FAPI and 18F-FDG PET/CT in cancer patients

PURPOSE : FAPI ligands (fibroblast activation protein inhibitor), a novel class of radiotracers for PET/CT imaging, demonstrated in previous studies rapid and high tumor uptake. The purpose of this study is the head-to-head intra-individual comparison of 68Ga- FAPI versus standard-of-care 18F-FDG in PET/CT in organ biodistribution and tumor uptake in patients with various cancers. MARERILA AND METHODS : This international retrospective multicenter analysis included PET/CT data from 71 patients from 6 centers who underwent both 68Ga-FAPI and 18F-FDG PET/CT within a median time interval of 10 days (range 1–89 days). Volumes of interest (VOIs) were manually drawn in normal organs and tumor lesions to quantify tracer uptake by SUVmax and SUVmean. Furthermore, tumor-to-background ratios (TBR) were generated (SUVmax tumor/ SUVmax organ). RESULTS : A total of 71 patients were studied of, which 28 were female and 43 male (median age 60). In 41 of 71 patients, the primary tumor was present. Forty-three of 71 patients exhibited 162 metastatic lesions. 68Ga-FAPI uptake in primary tumors and metastases was comparable to 18F-FDG in most cases. The SUVmax was significantly lower for 68Ga-FAPI than 18F-FDG in background tissues such as the brain, oral mucosa, myocardium, blood pool, liver, pancreas, and colon. Thus, 68Ga-FAPI TBRs were significantly higher than 18F-FDG TBRs in some sites, including liver and bone metastases. CONCLUSION : Quantitative tumor uptake is comparable between 68Ga-FAPI and 18F-FDG, but lower background uptake in most normal organs results in equal or higher TBRs for 68Ga-FAPI. Thus, 68Ga-FAPI PET/CT may yield improved diagnostic information in various cancers and especially in tumor locations with high physiological 18F-FDG uptake.Open Access funding by Projekt DEAL.http://link.springer.com/journal/259am2022Nuclear Medicin

Mechanical behavior of flexible silicon devices curved in spherical configurations

International audienceFoldable, stretchable and flexible electronics is of constant increasing interest since the early 2000's. Its applications spread from OLED-based displays, bio-inspired detectors and 'epidermal electronics'. Cylindrical curvature is largely studied through many 3 points and 4 points bending variations in electronic devices. However spherical curvature is poorly addressed, especially for monolithic approach. In this paper, a simulation and experiments of the elastic deformation of a thin silicon chip on a spherical holder are presented. The holder can have a concave or a convex shape. The chip is a square of 10 by 10 mm2. Its thickness is 50, 25 or 15 μm. The simulation is performed in 3 steps. First, the use of a shell model is validated by a convergence study and by a comparison with a 3D model and the literature. Then, the influence of the anisotropic elastic behavior (single crystal) is considered. In a given bulge test condition, isotropic and anisotropic silicon simulation gave similar deformations. At the end, the spherical forming is accomplished with a shell model and an anisotropic law. Experimental data is obtained by curving thin silicon plates of various thicknesses on different radii holders in a press. The comparison between experimental and computed results is realized. We found similar macroscopic deformations for both concave and convex shapes. The influence of chip thickness and applied pressure is studied on characteristic folds and flat part amplitudes. A heterogeneous stress distribution with hundreds of MPa variations can explain the difference observed between curved chips and perfect spherical holders. The stress level in electrical and optical active layers of thin curved silicon-based devices may affect their properties. A numerical example on a bolometer gives a stress-induced resistivity variation over 10

Integration of advanced optical functions near the focal plane array: first steps toward the on-chip infrared camera

International audienceToday, both military and civilian applications require miniaturized and cheap optical systems. The miniaturization of imaging systems leads to breakthroughs in optical design. Multichannel systems, inspired by the compound eyes of insects, offer great opportunities as the principle is to divide the information contained in the whole scene into the different optical channels. An interesting approach is to take advantage of the infrared focal plane array technology and environment to integrate these systems near the detector, leading to very compact architectures. This paper presents a compact optical architecture based on a multichannel imaging system entirely integrated in the dewar used to cool the detector. This work gives encouraging results to prepare the next step in the miniaturization of optical systems, which is the integration of the imaging function directly on the focal plane array (wafer-level integration), leading to the design of an on-chip infrared camera

A Fluxless and Low-Temperature Flip Chip Process Based on Insertion Technique

International audienceAbstract: For heterogeneous materials assembly, the thermal expansion mismatch between the chip and the substrate is a roadblock for Hip chip bonding of ultrafine-pitch (= 20 mm). Residual strains in bumps and device warpage have been calculated to evaluate the thermomechanical limits of a conventional flip chip soldering process using micro bumping. As a solution to overcome these limits, this paper describes a new patented flip-chip technology representing a technological breakthrough compared to conventional methods such as soldering or bonding through conductive adhesives. Electrical connections are performed by the insertion of metallic micro-tips in a ductile material. As a low-temperature process and fluxless technology, this method is adapted to fine-pitch and large devices. As a proof of concept, we present the bonding results obtained on fine-pitch large arrays of daisy chains with 500 x 500 contacts and 30-mu m pitch. The electrical contact has been demonstrated and characterized in terms of resistance and yield

Demonstration of an infrared microcamera inspired by Xenos Peckii vision

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