Wafer-scale integration of piezoelectric actuation capabilities in nanoelectromechanical systems resonators

In this work, we demonstrate the integration of piezoelectric actuation means on arrays of nanocantilevers at the wafer scale. We use lead titanate zirconate (PZT) as piezoelectric material mainly because of its excellent actuation properties even when geometrically constrained at extreme scal

Wafer-scale integration of piezoelectric actuation capabilities in nanoelectromechanical systems resonators

In this work, we demonstrate the integration of piezoelectric actuation means on arrays of nanocantilevers at the wafer scale. We use lead titanate zirconate (PZT) as piezoelectric material mainly because of its excellent actuation properties even when geometrically constrained at extreme scal

Développement d’un insecte artificiel. Nanodrone dédié à la surveillance intra-bâtiment

Dans l’optique de réaliser de la surveillance intra-bâtiment avec un système autonome, mobile, très discret, des recherches sont en cours pour développer des nanodrones. Elles se concentrent sur la compréhension et l’imitation du vol battu des insectes et sur les aspects de la miniaturisation. Cet article décrit la conception et la réalisation d’un insecte artificiel à ailes résonantes à l’aide des technologies de microfabrication de la microélectronique. Un actionneur électromagnétique induit un mouvement de flexion/torsion des ailes correspondant à une cinématique similaire à celle des insectes. L’estimation des phénomènes aéroélastiques en grands déplacements est réalisée à l’aide d’un modèle basé sur les éléments finis et une formulation analytique de l’aérodynamique. Une validation expérimentale est ensuite proposée

The price of tumor control: an analysis of rare side effects of anti-CTLA-4 therapy in metastatic melanoma from the ipilimumab network

Background: Ipilimumab, a cytotoxic T-lymphocyte antigen-4 (CTLA-4) blocking antibody, has been approved for the treatment of metastatic melanoma and induces adverse events (AE) in up to 64% of patients. Treatment algorithms for the management of common ipilimumab-induced AEs have lead to a reduction of morbidity, e.g. due to bowel perforations. However, the spectrum of less common AEs is expanding as ipilimumab is increasingly applied. Stringent recognition and management of AEs will reduce drug-induced morbidity and costs, and thus, positively impact the cost-benefit ratio of the drug. To facilitate timely identification and adequate management data on rare AEs were analyzed at 19 skin cancer centers. Methods and Findings: Patient files (n = 752) were screened for rare ipilimumab-associated AEs. A total of 120 AEs, some of which were life-threatening or even fatal, were reported and summarized by organ system describing the most instructive cases in detail. Previously unreported AEs like drug rash with eosinophilia and systemic symptoms (DRESS), granulomatous inflammation of the central nervous system, and aseptic meningitis, were documented. Obstacles included patientś delay in reporting symptoms and the differentiation of steroid-induced from ipilimumab-induced AEs under steroid treatment. Importantly, response rate was high in this patient population with tumor regression in 30.9% and a tumor control rate of 61.8% in stage IV melanoma patients despite the fact that some patients received only two of four recommended ipilimumab infusions. This suggests that ipilimumab-induced antitumor responses can have an early onset and that severe autoimmune reactions may reflect overtreatment. Conclusion: The wide spectrum of ipilimumab-induced AEs demands doctor and patient awareness to reduce morbidity and treatment costs and true ipilimumab success is dictated by both objective tumor responses and controlling severe side effects

Gravure par faisceau d'ions de films minces de titano-zirconate de plomb (PZT) (étude des dégradations engendrées et contribution à l'intégration aux microsystèmes)

Ces travaux, relatifs à la gravure par faisceau d'ions de films minces de PZT, présentent un ensemble de résultats pouvant être scindés en deux parties. Tout d'abord, nous avons mené une étude originale dont le but est de tenter d'appréhender les mécanismes d'interactions entre un faisceau d'ions (réactifs ou non) et la surface du PZT. Nous avons pu mettre en évidence diverses dégradations du matériau, aussi bien microstructurales qu'électriques, dégradations qui évoluent en fonction des paramètres de gravure, et en particulier du gaz utilisé (argon pur ou mélange Ar/CHF3). Notre objectif a alors été de distinguer l'implication de chaque contribution (bombardement ionique et réaction chimique) dans les modifications observées. En parallèle, dans un souci d'intégration du PZT aux microsystèmes, un travail d'optimisation des vitesses de gravures, du choix du masque et de la qualité des profils de gravure a été réalisé. Quelques exemples de réalisation de dispositifs intégrant une étape de gravure du PZT sont présentés.First of all, we have carried out an original study of which the aim is to try to understand the mechanisms of interactions between an ion beam (reactive or not) and the PZT surface. We have underlined various degradations of material, as well microstructural as electrical. These damages evolve according to the etching parameters and in particular the etching gas ( pure argon or Ar/CHF3 mixture). Then, the goal was to distinguish the implication from each contribution (ion bombardment and chemical reaction) in the modifications observed. Simultaneously, in concern for the PZT integration in microsystems, a work of optimization of etch rates, mask choice and quality of etching profiles has been performed. Some examples of realization of devices integrating a stage of PZT etching are presented.VALENCIENNES-BU Sciences Lettres (596062101) / SudocSudocFranceF

La douleur chez l'enfant (évolution des connaissances vers une meilleure prise en charge)

LIMOGES-BU Médecine pharmacie (870852108) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

Reactive ion beam etching effects on maskless PZT properties

Ion beam etching of sputtered Pb(Zr 0.54 ,Ti 0.46 )O 3 has been performed using pure Ar gas. The etch rate and selectivity ratios between PZT and masks as a function of the process parameters (current density, acceleration voltage, gas pressure) has been investigated. We have evaluated the PZT surface damage by contact mode AFM. It appears that the roughness increases after ion bombardment, and that the grain boundary zone is preferentially etched. For some etching parameters, we have also studied electrical damage. Carrying out C(V) and hysteresis loops P(E) measurements before and after etching have evidenced these degradation. We have noted a large permittivity decrease after etching process whatever the current density and the acceleration voltage. The ferroelectric damage was illustrated by a large increase of the average coercive field

(Zr/Ti) ratio effect on RF magnetron sputtered lead titanate zirconate films

Sputtered Pb(ZrxTi1−x)O3 thin films with various (Zr/Ti) compositions ranging from 15/85 to 70/30 were grown and characterised in terms of structural and electrical properties. PZT thin films, with 0.7–0.8μm thickness, were deposited on Si/SiO2/Ti/Pt by sputtering followed by conventional annealing. The sputtering conditions were the same for all the compositions. There were no apparent differences in crystallographic orientation as a function of Zr/Ti and the films a-lattice constant evolution is not exactly identical to the one of bulk ceramics. The permittivity increases when the Zr concentration increases and decreases just after the mor-photropic composition i.e. Zr-rich films. The ferroelectric properties are very sensitive to the Zr/Ti ratio. For example, the coercive field increases when the Ti concentration in the film increases