Development of Analytical Models of T- and U-shaped Cantilever-based MEMS Devices for Sensing and Energy Harvesting Applications

Dynamic-mode cantilever-based structures supporting end masses are frequently used as MEMS/NEMS devices in application areas as diverse as chemical/biosensing, atomic force microscopy, and energy harvesting. This paper presents a new analytical solution for the free vibration of a cantilever with a rigid end mass of finite size. The effects of both translational and rotational inertia as well as horizontal eccentricity of the end mass are incorporated into the model. This model is general regarding the end-mass distribution/geometry and is validated here for the commonly encountered geometries of T- and U-shaped cantilevers. Comparisons with 3D FEA simulations and experiments on silicon and organic MEMS are quite encouraging. The new solution gives insight into device behavior, provides an efficient tool for preliminary design, and may be extended in a straightforward manner to account for inherent energy dissipation in the case of organic-based cantilevers

Long-range and rapid transport of individual nano-objects by a hybrid electrothermoplasmonic nanotweezer

Plasmon-enhanced optical trapping is being actively studied to provide efficient manipulation of nanometre-sized objects. However, a long-standing issue with previously proposed solutions is how to controllably load the trap on-demand without relying on Brownian diffusion. Here, we show that the photo-induced heating of a nanoantenna in conjunction with an applied a.c. electric field can initiate rapid microscale fluid motion and particle transport with a velocity exceeding 10 μm s -1 , which is over two orders of magnitude faster than previously predicted. Our electrothermoplasmonic device enables on-demand long-range and rapid delivery of single nano-objects to specific plasmonic nanoantennas, where they can be trapped and even locked in place. We also present a physical model that elucidates the role of both heat-induced fluidic motion and plasmonic field enhancement in the plasmon-assisted optical trapping process. Finally, by applying a d.c. field or low-frequency a.c. field (below 10 Hz) while the particle is held in the trap by the gradient force, the trapped nano-objects can be immobilized into plasmonic hotspots, thereby providing the potential for effective low-power nanomanufacturing on-chip

Intelligence, reason of state and the art of governing risk and opportunity in early modern Europe

Drawing upon primary and secondary historical material, this paper explores the role of intelligence in early modern government. It focuses upon developments in seventeenth- and early-eighteenth-century England, a site-specific genealogical moment in the broader history of state power/knowledges. Addressing a tendency in Foucauldian work to neglect pre-eighteenth-century governance, the analysis reveals a set of interrelated processes which gave rise to an innovative technique for anticipating hazard and opportunity for the state. At the intersection of raison d’État, the evolving art of government, widespread routines of secrecy and a post-Westphalia field of European competition and exchange, intelligence was imagined as a fundamental solution to the concurrent problems of ensuring peace and stability while improving state forces. In the administrative offices of the English Secretary of State, an assemblage of complex and interrelated procedures sought to produce and manipulate information in ways which exposed both possible risks to the state and potential opportunities for expansion and gain. As this suggests, the art of intelligence played an important if largely unacknowledged role in the formation and growth of the early modern state. Ensuring strategic advantage over rivals, intelligence also limited the ability of England's neighbours to dominate trade, control the seas and master the colonies, functioning as a constitutive feature of European balance and equilibrium. As the analysis concludes, understanding intelligence as a form of governmental technique – a way of doing something – reveals an entirely novel way of thinking about and investigating its myriad (historical and contemporary) formations

Magneto-optical properties of the excited state of F centres in some alkali-halides

The orbital g-factor and the spin-orbit splittings of the first excited state of F-centres are measured in NaCl, NaBr, KBr and KF crystals by observing absorption and magnetic circular dichroism at various temperatures and using the moments method. Our experimental results and others are compared with Harker's theoretical values.Les auteurs ont mesuré le facteur de Landé orbital et la structure spin-orbite du premier état excité des centres F dans NaCl, NaBr, KBr et KF en analysant par la méthode des moments les courbes d'absorption et de dichroïsme circulaire magnétique à diverses températures. Ces résultats expérimentaux et ceux d'autres auteurs sont comparés aux valeurs théoriques calculées par Harker

Magneto-optical properties of the excited state of f- centres in some alkali-halides : addendum

The orbital g-factor and the spin-orbit splitting of the first excited state of F-centres are measured in KF, RbCl and RbBr crystals. Our experimental results and others are compared with Harker's theoretical values.Le facteur de Landé orbital et la structure spin-orbite du premier état excité des centres F. dans KF, RbCl et RbBr sont mesurés; ces résultats expérimentaux et ceux d'autres auteurs sont comparés aux valeurs théoriques calculées par Harker

Spectroscopie et fonctionnement laser de CaF2_{2}: Yb3+^{3+}

CaF$_{2 }$:Yb$^{3+}$ est un cristal doté de propriétés optiques et thermiques qui en font un matériau de choix pour divers types de fonctionnement laser. Un fonctionnement laser continu accordable entre 1000 et 1060nm et un rendement de conversion de 25% (par rapport au rayonnement de pompage optique incident) ont été déjà obtenus

On the electromechanical properties of organic semiconductors and OFET embedded MEMS

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