Self‐Healing Reduced Graphene Oxide Films by Supersonic Kinetic Spraying

The industrial scale application of graphene and other functional materials in the field of electronics has been limited by inherent defects, and the lack of simple deposition methods. A simple spray deposition method is developed that uses a supersonic air jet for a commercially available reduced graphene oxide (r‐GO) suspension. The r‐GO flakes are used as received, which are pre‐annealed and pre‐hydrazine‐treated, and do not undergo any post‐treatment. A part of the considerable kinetic energy of the r‐GO flakes entrained by the supersonic jet is used in stretching the flakes upon impact with the substrate. The resulting “frozen elastic strains” heal the defects (topological defects, namely Stone‐Wales defect and C₂ vacancies) in the r‐GO flakes, which is reflected in the reduced ratio of the intensities of the D and G bands in the deposited film. The defects can also be regenerated by annealing.     

Computer-aided diagnosis of solid breast nodules: use of an artificial neural network based on multiple sonographic features

A computer-aided diagnosis (CAD) algorithm identifying breast nodule malignancy using multiple ultrasonography (US) features and artificial neural network (ANN) classifier was developed from a database of 584 histologically confirmed cases containing 300 benign and 284 malignant breast nodules. The features determining whether a breast nodule is benign or malignant were extracted from US images through digital image processing with a relatively simple segmentation algorithm applied to the manually preselected region of interest. An ANN then distinguished malignant nodules in US images based on five morphological features representing the shape, edge characteristics, and darkness of a nodule. The structure of ANN was selected using k-fold cross-validation method with k = 10. The ANN trained with randomly selected half of breast nodule images showed the normalized area under the receiver operating characteristic curve of 0.95. With the trained ANN, 53.3% of biopsies on benign nodules can be avoided with 99.3% sensitivity. Performance of the developed classifier was reexamined with new US mass images in the generalized patient population of total 266 (167 benign and 99 malignant) cases. The developed CAD algorithm has the potential to increase the specificity of US for characterization of breast lesions.     

Performance Evaluation of Trellis Code Modulated oDQPSK Using the KLSE Method

A direct detection optical differential quadrature phase-shift keying (oDQPSK) system with trellis coded modulation (TCM) is proposed and analyzed. From the results obtained for the symbol-error rate, it is observed that the proposed oDQPSK-TCM system can perform about 5 dB better than the uncoded oDQPSK system. Optical signal-to-noise ratio penalty due to first-order polarization-mode dispersion of the proposed oDQPSK-TCM system is evaluated and compared with that of unequalized as well as electrically equalized oDQPSK systems.     

Evolution of Annealing Twins in Sputtered Cu Films

The Monte Carlo Potts model with n-fold method was used to simulate grain structure evolution in thin Cu films according to energetic competition principles. Surface/interface, grain boundary, and strain energy factors were applied to determine grain growth and crystallographic texture evolution as a function of film thickness. Furthermore, annealing twins were simulated through specific criteria that arbitrarily insert twin grains into the structure through grain boundary energy considerations. Four different types of microstructures were observed experimentally and simulated by the Monte Carlo technique.     

Smart Skin-Adhesive Patches: From Design to Biomedical Applications

With the advancement of medical and digital technologies, smart skin adhesive patches have emerged as a key player for complex medical purposes. In particular, skin adhesive patches with integrated electronics have created an excellent platform for monitoring health conditions and intelligent medication. However, the efficient design of the adhesive patches is still challenging as it requires a strong combination of network structure, adhesion, physical properties, and biocompatibility. To design an assimilated device, one must have a deep knowledge of various skin adhesive patches. This article provides a comprehensive review of the recent advances in skin-adhesive patches, including hydrogel-based adhesive patches, transdermal patches, and electronic skin (E-skin) patches, for various biomedical applications such as wound healing, drug delivery, biosensing, and health monitoring. Furthermore, the key challenges, implementable strategies, and future designs that can potentially provide researchers in designing innovative multipurpose smart skin patches are discussed. These advanced approaches are promising for managing the health and fitness of patients who require regular medical care.     

Through‐the‐glass spectroscopic ellipsometry for analysis of CdTe thin‐film solar cells in the superstrate configuration

Polycrystalline CdS/CdTe thin‐film solar cells in the superstrate configuration have been studied by spectroscopic ellipsometry (SE) using glass side illumination. In this measurement method, the first reflection from the ambient/glass interface is rejected, whereas the second reflection from the glass/film‐stack interface is collected; higher order reflections are also rejected. The SE analysis incorporates parameterized dielectric functions ε for solar cell component materials obtained by in situ and variable‐angle SE. In the SE analysis of the complete cells, a step‐wise procedure ranks the fitting parameters, including thicknesses and those defining the spectra in ε, according to their ability to reduce the root‐mean‐square deviation between the simulated and measured SE spectra. The best fit thicknesses from this analysis are found to be consistent with electron microscopy. Based on the SE results, the solar cell quantum efficiency (QE) can be simulated without any free parameters, and comparisons with measured QE enable optical model refinements as well as identification of optical and electronic losses. These capabilities have wide applications in photovoltaic module mapping and in‐line monitoring. Copyright © 2016 John Wiley & Sons, Ltd.     

Fabrication of polymeric large-core waveguides for opticalinterconnects using a rubber molding process

Polymeric large-core (47 μm×41 μm) optical waveguides for optical interconnects have been fabricated by using a rubber molding process. For low-cost low-loss large-core waveguides, our newly developed thick-photoresist patterning process is used for a master fabrication. Also a low-loss thermocurable polymer, perfluorocyclobutane (PFCB), is used in fabricating optical waveguides by rubber molding for the first time. The propagation loss is measured to be 0.4 dB/cm at the wavelength of 1.3 μm, and 0.7 dB/cm at the wavelength of 1.55 μm     

A Rigorous 2D Approximation Technique for 3D Waveguide Structures for BPM Calculations

We propose a rigorous 2D approximation technique for the 3D waveguide structures; it can minimize the well‐known approximation errors of the commonly used effective index method. The main concept of the proposed technique is to compensate for the effective cladding index in the equivalent slab model of the original channel waveguide from the modal effective index calculated by the nonuniform 2D finite difference method. With simulations, we used the proposed technique to calculate the coupling characteristics of a directional coupler by the 2D beam propagation method, and the results were almost exactly the same as the results calculated by the 3D beam propagation method.     

使用集成式负载开关和降压转换器组合 实现更可靠的USB调制解调器设计

在便携电子产品市场,无线网络的出现让人们能够随时随地进行高效的无线通信,而这正是设计便携式电子产品时的首要考虑因素之一。无线调制解调器是一种与无线网络而非电话系统连接的调制解调器。当用户连接无线调制解调器时,实际上就直接连接了无线互联网服务提供商。全球移动通信系统（GlobalSystemforMobile,GSM）和通用分包无线服务（GeneralPacketRadioService,GPRS）无线调制解调器均由uSB的VBUS线供电,提供了一种实现通用式便携设备环境的好方法。不过,这种调制解调器设计也带来了功率管理问题,因为GSM和GPRS发送器需要高达2A的峰值电流,而这却超过了USB电源的最大电流容量。