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Applying a constant voltage to superconducting nanowires we find that its IV-characteristic exhibits an unusual S-behavior. This behavior is the direct consequence of the dynamics of the superconducting condensate and of the existence of two different critical currents: jc2 at which the pure superconducting state becomes unstable and jc1 < jc2 at which the phase slip state is realized in the system. PACS numbers: 74.25. Op, 74.20.De, The majority of the experiments on the resistive state in quasi-one dimensional systems were performed in the constant current regime and at temperatures close to T c . It is extremely difficult to apply voltage to a superconductor because the current density induced by the applied electric field inevitably reaches the critical value and destroys superconductivity in the sample. The decrease of the superconducting current by the appearance of phase slip centers [1,2,3,4,5] is not effective in this case because of the large heating of the sample at low temperatures. At temperatures close to T c the heating can be suppressed due to the low value of the critical currents but in this case the applied electric field does not penetrate deep into the sample because of the existence of regions near the N-S boundary where the drop of the applied voltage occurs [6,7].This situation drastically changes with the appearance of nano-technology and the ability to create long (to allow the appearance of phase slip centers) superconducting wires with a small cross section (to decrease the effect of heating). In this Letter we present results on the behavior of such nanowires in the constant voltage regime. We found that the I-V characterestic in this case has a remarkable S-shape. Our theoretical analysis based on the time-dependent Ginzburg-Landau equations (TDGL) shows that such a behavior is a direct consequence of the dynamics of the superconducting condensate and we predict new unusual features which still need additional experimental study.The superconducting nanowires were prepared by electrodeposition into nanopores of homemade track-etched polycarbonate membranes [8]. For the lead nanowires, a 22 µm thick membrane (with pore diameter ∼ 40 nm and pore density ∼ 4·10 9 cm −2 ) and an aqueous solution of 40.4 g/l Pb(BF 4 ) 2 , 33.6 g/l HBF 4 and 15 g/l H 3 BO 3 were used [9], while in the case of the tin nanowires, a 50 µm thick membrane (with pore diameter ∼ 55 nm and pore density ∼ 2·10 9 cm −2 ) and an electrolyte of 41.8 g/l Sn(BF 4 ) 2 in water solution were applied. Constant potential of -0.5 V versus an Ag/AgCl reference electrode was used in a three-electrode configuration in order to reduce the Pb 2+ or Sn 2+ ions into the nanopores. As shown in Fig. 1, the nanowires are cylindrical and the diameter is uniform along their length. In order to perform elec-

We have developed a new reliable method combining template synthesis and nanolithography-based contacting technique to elaborate current perpendicular-to-plane giant magnetoresistance spin valve nanowires, which are very promising for the exploration of electrical spin transfer phenomena. The method allows the electrical connection of one single nanowire in a large assembly of wires embedded in anodic porous alumina supported on Si substrate with diameters and periodicities to be controllable to a large extent. Both magnetic excitations and switching phenomena driven by a spin-polarized current were clearly demonstrated in our electrodeposited NiFe/Cu/ NiFe trilayer nanowires. This novel approach promises to be of strong interest for subsequent fabrication of phase-locked arrays of spin transfer nano-oscillators with increased output power for microwave applications.

Experimental results on the phase slip process in superconducting lead nanowires are presented under two different experimental conditions: constant applied current or constant voltage. Based on these experiments we established a simple model which gives us the condition of the appearance of phase slip centers in a quasione-dimensional wire. The competition between two relaxations times ͑relaxation time of the absolute value of the order parameter ͉͉ and relaxation time of the phase of the order parameter in the phase slip center ) governs the phase slip process. Phase slips, as periodic oscillations in time of the order parameter, are only possible if the gradient of the phase grows faster than the value of the order parameter in the phase slip center, or equivalently if Ͻ ͉͉ .

Arrays of granular superconducting Pb and Sn nanowires (40–55 nm in diameter and 22 or 50 μm long) have been prepared by electrodeposition in nanoporous membranes. A simple technique has been developed to perform electrical transport measurement on a single nanowire. By sweeping the dc current inside the nanowire, we observed the formation of phase-slip-centers far below the critical temperature. In contrast, in voltage-driven experiments, an interesting S-shaped behavior has been observed in the nucleation region of these phase-slip-centers.

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Despite substantial advances in many different fields of neurorobotics in general, and biomimetic robots in particular, a key challenge is the integration of concepts: to collate and combine research on disparate and conceptually disjunct research areas in the neurosciences and engineering sciences. We claim that the development of suitable robotic integration platforms is of particular relevance to make such integration of concepts work in practice. Here, we provide an example for a hexapod robotic integration platform for autonomous locomotion. In a sequence of six focus sections dealing with aspects of intelligent, embodied motor control in insects and multipedal robots—ranging from compliant actuation, distributed proprioception and control of multiple legs, the formation of internal representations to the use of an internal body model—we introduce the walking robot HECTOR as a research platform for integrative biomimetics of hexapedal locomotion. Owing to its 18 highly sensorized, compliant actuators, light-weight exoskeleton, distributed and expandable hardware architecture, and an appropriate dynamic simulation framework, HECTOR offers many opportunities to integrate research effort across biomimetics research on actuation, sensory-motor feedback, inter-leg coordination, and cognitive abilities such as motion planning and learning of its own body size.

This paper presents a mathematical model developed for predicting the temperature-pressure behavior and gas generation inside 18650 LCO/Graphite cells with a DMC (Dimethyl Carbonate) electrolyte. The cell was modeled using oven heating conditions, and the analysis was done at time intervals around the venting event. The paper also presents the thermodynamic property table for DMC, as extracted from different resources and calculated using various assumptions. The model was developed by deriving the energy balance for an unsteady-flow control volume and applying the isentropic flow equations corresponding to the venting of gas. The results show that the model fails to predict the pressure measured experimentally when no gas is generated inside. When adding the gas generation due to pre-venting reactions occurring, the model can predict the pressure profile measured experimentally.