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The article discusses the synthesis of electrically and magnetically dual-driven Janus particles for a handwriting-enabled twisting ball display. A twisting ball display is created using Janus particles, the electric color control and handwriting are tested using a magnet, and the findings are revealed. The technology presented here can be applied to low-cost, lightweight, highly visible, and energy-saving electronic message boards and large whiteboards.

Studies of voltage-induced deflections in electroactive paper (EAPap) have been carried out. On the experimental side, measurements of bias-dependent deflections and strain, water absorption as a function of time, and relative humidity were obtained for the cellulose EAPap actuator. In addition, model simulations have also been carried out to probe and quantify the role of the various internal mechanisms responsible for the deflection. Our simulation predictions yield good agreement with the measured deflection data for the EAPap. The modeling suggests that internal ion content and its migration, water absorption leading to a nonuniform permittivity, random variations in the transverse piezoelectric-coupling coefficient d31,i, and the modulus of elasticity all collectively contribute to the EAPap deflection electrophysics. It also appears that higher sensitivity, with a minimal bias dependence, could be achieved by deliberately adding ions during EAPap processing. [ABSTRACT FROM AUTHOR]

The article reports fabrication of reduced graphene oxide (rGO) films using chemical reduction by hydrazine hydrate and rGO paper-like samples using low temperature treatment reduction. Structural analysis confirms the formation of the rGO structure for both samples. It demonstrates a simplified way for the fabrication of rGO paper that possesses better and easier measurable macroscopic electrical properties than that of rGO thin film.

Presents a model for the electrostatic detection apparatus. Why the model was developed; Information on the experimental evidence provided to support the model; Role of Mylar-paper in the detection apparatus; Detailed information on the model presented.

The article introduces a new method developed to study the ink-paper interface and the structural variations of a deposited layer of ink. High-resolution x-ray tomography and laser ablation are used to determine the depth profile of ink (toner) in a paper substrate, while X-ray tomography is used to produce the 3D structure of paper with about 1?mum spatial resolution. It is concluded that a toner layer on a light-weight-coated paper substrate is disturbed by protruding fibers of the base paper.

The highly stable superparamagnetic iron oxide nanoparticles (SPION), functionalized with polyethylene glycol (PEG) are prepared. The PEG chains at PEG-SPION's surface provide a good permeability and strong affinity between the bacterial cellulose (BC) chains and SPION through hydrogen-bonding interactions. PEG-SPION allows the incorporation of higher content of nanoparticles without compromising the mechanical properties of the nanocomposite.

Over the last decade, gallium nitride (GaN) has emerged as an excellent material for the fabrication of power devices. Among the semiconductors for which power devices are already available in the market, GaN has the widest energy gap, the largest critical field, and the highest saturation velocity, thus representing an excellent material for the fabrication of high-speed/high-voltage components. The presence of spontaneous and piezoelectric polarization allows us to create a two-dimensional electron gas, with high mobility and large channel density, in the absence of any doping, thanks to the use of AlGaN/GaN heterostructures. This contributes to minimize resistive losses; at the same time, for GaN transistors, switching losses are very low, thanks to the small parasitic capacitances and switching charges. Device scaling and monolithic integration enable a high-frequency operation, with consequent advantages in terms of miniaturization. For high power/high-voltage operation, vertical device architectures are being proposed and investigated, and three-dimensional structures—fin-shaped, trench-structured, nanowire-based—are demonstrating great potential. Contrary to Si, GaN is a relatively young material: trapping and degradation processes must be understood and described in detail, with the aim of optimizing device stability and reliability. This Tutorial describes the physics, technology, and reliability of GaN-based power devices: in the first part of the article, starting from a discussion of the main properties of the material, the characteristics of lateral and vertical GaN transistors are discussed in detail to provide guidance in this complex and interesting field. The second part of the paper focuses on trapping and reliability aspects: the physical origin of traps in GaN and the main degradation mechanisms are discussed in detail. The wide set of referenced papers and the insight into the most relevant aspects gives the reader a comprehensive overview on the present and next-generation GaN electronics. [ABSTRACT FROM AUTHOR]

A model for ultracapacitor capacitance and ion screening length based on semiconductor physics is presented in this paper. Screening length is related to capacitance as the plate-plate separation in a double-layer, and thus both are related to dissolved ion density in the electrolyte. Furthermore, this dissolved ion density can be expressed in terms of an effective bandgap assigned to the electrolyte/solvent pair. Therefore, by knowing the effective bandgap, we can explain the published experimental measurements of the dependence of capacitance and screening length on temperature. For electrolytes commonly used in ultracapacitor applications, the effective bandgap is estimated to be on the order of a few 100 meV. [ABSTRACT FROM AUTHOR]

A novel 2-D Halbach permanent magnet array which can be used in magnetically levitated planar motor is proposed in this paper. The air-gap flux density distribution of the novel 2-D Halbach permanent magnet array is solved by the scalar magnetic potential equation. In order to compare with the well-known Halbach magnet array that was used by Jansen et al. [IEEE Trans. Ind. Appl. 44(4), 1108 (2008)], harmonic analysis of the x- and z- component of the air-gap flux density are carried out by Fourier decomposition. Comparison of Bx and Bz between the two 2-D Halbach magnet arrays are made. And it is verified that the performance of the new Halbach magnet array is superior to the existing Halbach magnet arrays, its higher magnetic flux density and lower high-order harmonics will help to improve the performance of the magnetically levitated planar motor. [ABSTRACT FROM AUTHOR]

A model is described that enables the calculation of thin-film transistor (TFT) characteristics starting from fundamental considerations of charge transport. Starting from scattering mechanisms and trap distribution in a semiconductor, electric field and charge density distributions are calculated along the channel length direction. Output and transfer characteristics of a TFT can be calculated at any temperature. The model is quasi-two-dimensional and is based on multiple trap and release transport in the semiconductor active layer. Importantly, the charge transport models that constitute the basis of this paper are very sophisticated and operate at a level of depth and detail that go beyond most other studies on thin-film transistors. Contact resistance effects, often very important in TFTs, are included in the model. Simulation results are presented for several representative TFT dimensions and parameter sets. The model is designed for convenient use by the research community, and the source code as well as instructions are publicly available. The modular nature of the models allows for ease in changing the semiconductor parameters, transport mechanisms, contact barriers, etc. [ABSTRACT FROM AUTHOR]

While this may be clear, the editors of the journal asked: What can we do better to meet the needs of the applied physics community? Bob Birtcher deserves special applause for being one of the longest serving editors in the journal history: he began work on the journal in 1990 when physical papers were handled manually at the journal office at Argonne. [Extracted from the article]

This paper provides a tutorial overview over recent vigorous efforts to develop computing systems based on spin waves instead of charges and voltages. Spin-wave computing can be considered a subfield of spintronics, which uses magnetic excitations for computation and memory applications. The Tutorial combines backgrounds in spin-wave and device physics as well as circuit engineering to create synergies between the physics and electrical engineering communities to advance the field toward practical spin-wave circuits. After an introduction to magnetic interactions and spin-wave physics, the basic aspects of spin-wave computing and individual spin-wave devices are reviewed. The focus is on spin-wave majority gates as they are the most prominently pursued device concept. Subsequently, we discuss the current status and the challenges to combine spin-wave gates and obtain circuits and ultimately computing systems, considering essential aspects such as gate interconnection, logic level restoration, input–output consistency, and fan-out achievement. We argue that spin-wave circuits need to be embedded in conventional complementary metal–oxide–semiconductor (CMOS) circuits to obtain complete functional hybrid computing systems. The state of the art of benchmarking such hybrid spin-wave–CMOS systems is reviewed, and the current challenges to realize such systems are discussed. The benchmark indicates that hybrid spin-wave–CMOS systems promise ultralow-power operation and may ultimately outperform conventional CMOS circuits in terms of the power-delay-area product. Current challenges to achieve this goal include low-power signal restoration in spin-wave circuits as well as efficient spin-wave transducers. [ABSTRACT FROM AUTHOR]

In the present paper, a model with two adjustable parameters is developed to study the viscosity of liquid as a function of pressure. The model so developed has been applied in 38 liquids. The computed results have been found to be in very good agreement with the experimental data in case of each liquid. The minimum and the maximum ranges of viscosity studied in the present paper are 0.054–0.515 cp in CO2 and 16.9–57 200.0 cp in 2-ethylhexyl-benzoate, respectively. It is interesting to note that the relation is found valid even in the liquid in which the viscosity varies by a factor of 3400, i.e., 2-ethylhexyl-benzoate. [ABSTRACT FROM AUTHOR]