Search results for "DEVICES"
showing 10 items of 615 documents
Optical Forging of Graphene into Three-Dimensional Shapes
2017
Atomically thin materials, such as graphene, are the ultimate building blocks for nanoscale devices. But although their synthesis and handling today are routine, all efforts thus far have been restricted to flat natural geometries, since the means to control their three-dimensional (3D) morphology has remained elusive. Here we show that, just as a blacksmith uses a hammer to forge a metal sheet into 3D shapes, a pulsed laser beam can forge a graphene sheet into controlled 3D shapes in the nanoscale. The forging mechanism is based on laser-induced local expansion of graphene, as confirmed by computer simulations using thin sheet elasticity theory. peerReviewed
Dynamics of human cancer cell lines monitored by electrical and acoustic fluctuation analysis.
2010
Early determination of the metastatic potential of cancer cells is a crucial step for successful oncological treatment. Besides the remarkable progress in molecular genomics- or proteomics-based diagnostics, there is a great demand for in vitro biosensor devices that allow rapid and selective detection of the invasive properties of tumor cells. Here, the classical cancer cell motility in vitro assays for migration and invasion relying on Boyden chambers are compared to a real-time biosensor that analyzes the dynamic properties of adherent cells electro-acoustically with a time resolution on the order of seconds. The sensor relies on the well-established quartz crystal microbalance technique…
Origin of the Chemiresistive Response of Ultrathin Films of Conductive Metal–Organic Frameworks
2018
Conductive metal-organic frameworks are opening new perspectives for the use of these porous materials for applications traditionally limited to more classical inorganic materials, such as their integration into electronic devices. This has enabled the development of chemiresistive sensors capable of transducing the presence of specific guests into an electrical response with good selectivity and sensitivity. By combining experimental data with computational modelling, a possible origin for the underlying mechanism of this phenomenon in ultrathin films (ca. 30 nm) of Cu-CAT-1 is described. ispartof: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION vol:57 issue:46 pages:15086-15090 ispartof: location…
Graphene Oxide Carboxymethylcellulose Nanocomposite for Dressing Materials.
2020
Sore, infected wounds are a major clinical issue, and there is thus an urgent need for novel biomaterials as multifunctional constituents for dressings. A set of biocomposites was prepared by solvent casting using different concentrations of carboxymethylcellulose (CMC) and exfoliated graphene oxide (Exf-GO) as a filler. Exf-GO was first obtained by the strong oxidation and exfoliation of graphite. The structural, morphological and mechanical properties of the composites (CMCx/Exf-GO) were evaluated, and the obtained composites were homogenous, transparent and brownish in color. The results confirmed that Exf-GO may be homogeneously dispersed in CMC. It was found that the composite has an i…
Strain-controlled domain wall injection into nanowires for sensor applications
2021
We investigate experimentally the effects of externally applied strain on the injection of 180$^\circ$ domain walls (DW) from a nucleation pad into magnetic nanowires, as typically used for DW-based sensors. In our study the strain, generated by substrate bending, induces in the material a uniaxial anisotropy due to magnetoelastic coupling. To compare the strain effects, $Co_{40}Fe_{40}B_{20}$, $Ni$ and $Ni_{82}Fe_{18}$ samples with in-plane magnetization and different magnetoelastic coupling are deposited. In these samples, we measure the magnetic field required for the injection of a DW, by imaging differential contrast in a magneto-optical Kerr microscope. We find that strain increases t…
MATERIALS AND PROCESSING ISSUES FOR THE MANUFACTURING OF INTEGRATED PASSIVE AND ACTIVE DEVICES ON FLEXIBLE SUBSTRATES
2008
Plast_ICs is a Public/Private Laboratory funded by Italian Government aimed to build a novel technological platform for the development of flexible electronics, mainly, but not solely, based on thin inorganic films. Integration of different functions, on single and/or multiple plastic foils, to generate a smart system is the final goal of the project. The building blocks of the platform will be presented, starting from the different plastic substrates characterization, going through the development of active devices, such as thin-film- transistors, and passive devices, like thin-film- resistors, capacitors, inductors. Fully inorganic elementary devices, based on optical patterning and in va…
Operating Modes of Sandwiched Light-Emitting Electrochemical Cells
2011
Light-emitting electrochemical cells (LECs) are promising lighting devices in which the redistribution of ionic charges allows for double electronic carrier injection from air-stable electrodes. Uncertainties about the mode of operation are limiting the progress of these devices. Using fast (with respect to the current growth time) but resolutive electrical measurement techniques, the electronic transport mechanism in state-of-the-art sandwiched devices can be monitored as a function of the operation time. The results indicate the formation of doped transport layers adjacent to the electrodes that reduces the extent of the central neutral light-emitting layer where electronic transport is l…
Large area perovskite light-emitting diodes by gas-assisted crystallization:
2019
Halide perovskites have been gaining considerable attention recently for use in light-emitting applications, due to their bandgap tunability, color purity and low cost fabrication methods. However, current fabrication techniques limit the processing to small-area devices. Here, we show that a facile N 2 gas-quenching technique can be used to make methylammonium lead bromide-based perovskite light-emitting diodes (PeLEDs) with a peak luminance of 6600 cd m −2 and a current efficiency of 7.0 cd A −1 . We use this strategy to upscale PeLEDs to large-area substrates (230 cm 2 ) by developing a protocol for slot-die coating combined with gas-quenching. The resulting large area devices (9 device…
Smart composite films of nanometric thickness based on copper-iodine coordination polymers. Toward sensors.
2018
One-pot reactions between CuI and methyl or methyl 2-amino-isonicotinate give rise to the formation of two coordination polymers (CPs) based on double zig-zag Cu2I2 chains. The presence of a NH2 group in the isonicotinate ligand produces different supramolecular interactions affecting the Cu-Cu distances and symmetry of the Cu2I2 chains. These structural variations significantly modulate their physical properties. Thus, both CPs are semiconductors and also show reversible thermo/mechanoluminescence. X-ray diffraction studies carried out under different temperature and pressure conditions in combination with theoretical calculations have been used to rationalize the multi-stimuli-responsive …
New concepts and applications in macromolecular chemistry of fullerenes
2010
A new classification on the different types of fullerene-containing polymers is presented according to their different properties and applications they exhibit in a variety of fields. Because of their interest and novelty, water-soluble and biodegradable C(60)-polymers are discussed first, followed by polyfullerene-based membranes where unprecedented supramolecular structures are presented. Next are compounds that involve hybrid materials formed from fullerenes and other components such as silica, DNA, and carbon nanotubes (CNTs) where the most recent advances have been achieved. A most relevant topic is still that of C(60)-based donor-acceptor (D-A) polymers. Since their application in pho…