The production of materials that contain more than one functional constituent, the so-called multifunctional materials, is quite relevant in advanced technology. By acting as building blocks, nanoparticles can be suitably explored for generating higher-order multifunctional structures. In this regard, herein, a special clustered magneto-fluorescent superstructure has been developed for non-destructive detection of flaws and shallow subsurface discontinuities in industrial ferromagnetic materials. The strategy consists of the solvophobic-controlled assembly of organic-based maghemite cores and water-based II–VI quantum dots, in the presence of hexadecyltrimethyl-ammonium bromide, CTAB, as a compatibilizer agent. This composite exhibited a high magnetic response (σmax = 66 emu g−1) and uniform size, in addition to tunable optical properties (QY = 78%). The strategy of utilizing nanoparticles as magneto-fluorescent nanoprobes to identify tiny slits represents a great advance, for improving the capability of precisely revealing the fracture boundary locations by visual real-time inspection. The nanoscale probes exhibit a low signal-to-noise ratio and a higher competitive performance in relation to the existing micrometric detection systems.
We integrated graphene with asymmetric metal metasurfaces and optimised the geometry dependent photoresponse towards optoelectronic molecular sensor devices. Through careful tuning and characterisation, combining finite-difference time-domain simulations, electron-beam lithography-based nanofabrication, and micro-Fourier transform infrared spectroscopy, we achieved precise control over the mid-infrared peak response wavelengths, transmittance, and reflectance. Our methods enabled simple, reproducible and targeted mid-infrared molecular sensing over a wide range of geometrical parameters. With ultimate minimization potential down to atomic thicknesses and a diverse range of complimentary nanomaterial combinations, we anticipate a high impact potential of these technologies for environmental monitoring, threat detection, and point of care diagnostics.
Computational efficiency is significantly enhanced using artificial neural network-based computing. A two-terminal memristive device is a powerful electronic device that can mimic the behavior of a biological synapse in addition to storing information and performing logic operations. This work focuses on the fabrication of a memristive device that utilizes a resistive switching layer composed of polyvinyl alcohol infused with ZnO nanoparticles. By incorporating ZnO nanoparticles into the polymer film, the fabricated memristive devices exhibit functionalities that closely resemble those of biological synapses, including short-term and long-term plasticity, paired-pulse facilitation, and spike time-dependent plasticity. These findings establish the ZnO nanoparticle-polymer nanocomposite as a highly promising material for future neuromorphic systems.
Infrared radiation reflection and transmission of a single layer of gold micropatch two-dimensional arrays, of patch length ∼m and width ∼m, have been carefully studied by a finite-difference time-domain (FDTD) method, and Fourier-transform infrared spectroscopy (FTIR). Through precision design of the micropatch array structure geometry, we achieve a significantly enhanced reflectance (85%), a substantial diffraction (10%), and a much reduced transmittance (5%) for an array of only 15% surface metal coverage. This results in an efficient far-field optical coupling with promising practical implications for efficient mid-infrared photodetectors. Most importantly we find that the propagating electromagnetic fields are transiently concentrated around the gold micropatch array in a time duration of tens of ns, providing us with a novel efficient near-field optical coupling.