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Auâ€"Ag nanostructures comprising of ∼1 nm Ag nanoparticles embedded into an Au matrix show several unconventional optical, electric and magnetic properties. Here, we review progress made towards the preparation of these materials as well as analysis of their structure. Further, electrical and magnetic transitions in these materials are discussed. Finally, we review the properties of these materials as revealed from optical and electron microscopic probes. [ABSTRACT FROM AUTHOR]

Van der Waals (vdW) heterostructure is a type of metamaterial where multiple layers of 2D materials are vertically aligned at controlled misorientation. The relative rotation in between the adjacent layers, or the twist angle between them plays a crucial role in changing the electronic band structure of the superlattice. The assembly of multi-layers of precisely twisted two dimensional layered materials requires knowledge of the atomic structure at the edge of the flake. It may be artificially created by the 'tear and stack' process. Otherwise, the crystallographic orientation needs to be determined through invasive processes such as transmission electron microscopy or scanning tunneling microscopy, and via second-harmonic generation (SHG). Here, we demonstrate a simple and elegant transfer protocol using only an optical microscope as a edge identifier tool through which, controlled transfer of twisted homobilayer and heterobilayer transition metal dichalcogenides is performed with close to 100% yield. The fabricated twisted vdW heterostructures have been characterized by SHG, Raman spectroscopy and photoluminiscence spectroscopy, confirming the desired twist angle within ∼0.5° accuracy. The presented method is reliable, quick and prevents the use of invasive tools which is desirable for reproducible device functionalities. [ABSTRACT FROM AUTHOR]

This paper reports on the use of electrolyte-enabled distributed transducers in a polymer-based microfluidic device for the detection of distributed static and dynamic loads. The core of the device is a polymer rectangular microstructure integrated with electrolyte-enabled distributed transducers. Distributed loads acting on the polymer microstructure are converted to different deflections along the microstructure length, which are further translated to electrical resistance changes by electrolyte-enabled distributed transducers. Owing to the great simplicity of the device configuration, a standard polymer-based fabrication process is employed to fabricate this device. With custom-built electronic circuits and custom LabVIEW programs, fabricated devices filled with two different electrolytes, 0.1 M NaCl electrolyte and 1-ethyl-3- methylimidazolium dicyanamide electrolyte, are characterized, demonstrating the capability of detecting distributed static and dynamic loads with a single device. As a result, the polymer-based microfluidic device presented in this paper is promising for offering the capability of detecting distributed static and dynamic loads in biomedical/surgical, manufacturing and robotics applications. [ABSTRACT FROM AUTHOR]

We report the observation of linear magneto-resistance (LMR) with a very low cross-over magnetic field (Bc) at room temperature in bismuth(110) thin films fabricated using thermal evaporation. The magneto-resistance at different temperatures (T) indicate that Bc has a strong T-dependence, and displays a remarkably small magnitude of 180 mT at T = 300 K. The parameter Φ, defined as the MR% (B = 1 T)/ Bc is 248, is considerably higher at room temperature compared to values previously reported in literature. The observed LMR is likely due to the recombination of carriers in compensated systems near charge neutrality. Our measurements demonstrate that the LMR can be observed at a very low field and high T, which can be utilized in a variety of applications. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate-based nanocomposites with hexagonal boron nitride nanosheets (BNNs) were prepared by a solution casting method with varying concentrations of BNNs from 0.5 wt% to 4 wt%. Melting and crystallization behaviour of the composites were investigated by differential scanning calorimetry, which suggests that with increasing presence of nanosheets, the crystallinity increases and hence the polyethylene terephthalate chain mobility gets restricted, which leads to suppression of crystal growth. The nanoindentation measurements on the composite films exhibit improved mechanical properties. Enhancement of 33.3% of elastic modulus and 32.4% of hardness was observed with 2 wt% infusion of boron nitride nanosheets in polyethylene terephthalate. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive study on the performance of a polydimethylsiloxane-based microfluidic device for the detection of continuous distributed static and dynamic loads. The core of this device is a single-compliant polymer microstructure integrated with a set of electrolyte-enabled distributed transducers, which are equally spaced along the microstructure length. The microstructure converts continuous distributed loads to continuous deflection, which is translated to discrete resistance changes by the distributed transducers. One potential application of this device is to measure spatially varying elasticity/viscoelasticity of a heterogeneous soft material, through quasi-static, stress relaxation and dynamic mechanical analysis tests. Thus, by controlling the displacement of a rigid probe, three types of loads (i.e., static, step and sinusoidal) are exerted on the device, and the performance of the device is experimentally characterized and analytically examined. As a result, this work establishes not only an experimental method for characterizing the performance of the device under various loading conditions, which can be directly adopted to measure the spatially varying elasticity/viscoelasticity of a heterogeneous soft material, but also the correlation of the device performance to its design parameters. [ABSTRACT FROM AUTHOR]