1,721,363 research outputs found
Vie privée : film, extraits / Carpi (F.) et son orchestre
No full textComprend : Sidonie / Cros (Charles), texte, Rivière (J. M.), Spanos (Y.), arrgt. de Mauriat (Paul) ; Bardot (Brigitte), chant - Leçon de danse / Carpi (F.) - Thème de Vie privée / Carpi (F.) - Concerto / Carpi (F.)BnF-Partenariats, Collection sonore - BelieveContient une table des matière
Improving performance of electro-active polymers (EAPs) via Corona Charging
No full textThe main problem of dielectric elastomer (DE) actuators is today represented by the high driving electric fields (orders of 10‐100 V/μm) necessary for their activation. Although several attempts have been made in order to increase strains by enhancing the dielectric constant (ε) of such matrices and keeping low elastic moduli (Y) to control the ε/Y ratio, currently several challenges have still to be faced. In this work, a new approach is presented to enhance the electromechanical performance of DE actuators. Soft elastomeric polyurethane (PU) matrices with foam structure were electrically charged and poled via Corona process. Such matrices showed electret‐like properties, possibly due to the presence of macro‐dipoles induced both at the matrix/pore surfaces and inside the bulk. Morphological (SEM, Bet), dielectric and dynamic‐mechanical (DMA) tests were performed in order to characterize the material. Results showed that corona charging may represent a new promising route to obtain dielectric elastomers with improved dielectric properties
Controlled navigation of endoscopic capsules: concept and preliminary experimental investigations
No full textThis paper describes a technique to control the navigation of traditional wireless endoscopic capsules and reports preliminary proof-of-concept investigations. These capsules are used for noninvasive explorations of the digestive tube. At present, their motion cannot be controlled and they proceed by means of the visceral peristalsis. In order to enable motion controls, the technique proposed here adopts magnetic shells which are to be applied to available capsules, immediately before their use. The shells are used to control the capsule movement by means of external magnetic fields. This solution is readily applicable to any endoscopic capsule, avoiding internal modifications. Prototype elastic shells made of silicone elastomers mixed with magnetic particles were fabricated. They were tested with the most diffused capsule (model M2A, Given Imaging Ltd., Yoqneam, Israel), by studying the performance of the capsule/shell complex in simplified experimental conditions. Bench tests permitted to demonstrate controlled translations, rotations, and rototranslations of the capsule/shell complex within tubular structures coated with pieces of bovine tissues. The use of a new instrumentation, recently developed for cardiovascular treatments, is proposed as a potential means enabling the application of controlled magnetic fields for intrabody navigations
Magnetic shells for gastrointestinal endoscopic capsules as a means to control their motion
No full textWireless endoscopic video capsules are becoming largely used today for non-invasive explorations of the digestive tube. Traditional types of such capsules present a major drawback: their motion can not be controlled, since they proceed by means of the visceral peristalsis only. In order to enable a wireless control of their motion, this paper describes a new concept based on the use of external magnetic fields. The proposed technique exploits magnetic shells to be applied to traditional capsules prior to their use. The shells are capable of interacting with an imposed external magnetic field, providing a means to control the capsule movement and orientation. This solution is readily and cheaply applicable to any commercial endoscopic capsule, avoiding internal modifications. The paper reports results of preliminary bench tests. Prototype elastic shells made of a silicone elastomer mixed with magnetic particles were fabricated and tested with the Given Imaging M2A capsule in simplified experimental conditions. These tests permitted to demonstrate translations, rotations and roto-translations of the capsule/shell complex onto pieces of bovine tissues
Realization of conducting polymer actuators using a controlled volume microsyringe system
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