Search results for "FABRICATION"

Fiber-Optic Aqueous Dipping Sensor Based on Coaxial-Michelson Modal Interferometers

2009

Fiber-optic modal interferometers with a coaxial-Michelson configuration can be used to monitor aqueous solutions by simple dipping of few centimeters of a fiber tip. The fabrication of these sensors to work around 850 nm enables the use of compact, robust, and low-cost optical spectrum analyzers. The use of this type of portable sensor system to monitor sewage treatment plants is shown.

Reliability and Fabrication of Molds for Nanoimprinting

2010

During the last decade there has been a growing attention to nanoscaled materials and to the related technologies to produce them. The problems to overcome in the manufacturing of these kinds of items increase dramatically on decreasing the dimension of the devices. In this sense, the scientific research has been strongly stimulated to try to improve and optimize all the critical issues. One of the most attractive fields in nanomanufacturing is related to nanoimprinting, i.e. to the possibility to transfer a nanoscaled pattern from a mold to another substrate. In this technology, among the others, there are two main critical steps: the preparation of a good mold and the use of a correct rel…

Electrochemical Fabrication of Inorganic/Organic Field Effect Transistor

2010

After discovery of conducting polymers and the possibility to modify their electrical properties (from insulating to metallic-like behaviour) by doping and a careful choice of the processing conditions, a large amount of research effort has been devoted to the theoretical understanding of their solid state properties as well as to exploit the possible application of conducting polymers in many technological fields including: large area organic electronics, polymer photovoltaic cell and sensors (1-2). Organic thin-film transistors appears very promising for the development of low cost, flexible and disposable plastic electronics. In order to reduce the operating voltage it has been suggested…

Electrochemical fabrication of Cu2O/TiO2 nanotubes junctions with visible light photoactivity

2013

Electrochemical fabrication of amorphous TiO2/Poly-3,4 Ethylenedioxythiophene (PEDOT) hybrid structures for electronic devices.

2013

Fabrication and Characterization of Chitosan-Heteropolyacid complex as membranes for low temperature H2-O2 fuel cell

2015

In this work we describe an easy procedure to fabricate homogeneous CS-HPA polyelectrolyte films using phosphotungstic acid (PTA) as cross-linking agent. The re action between CS chains and PTA is controlled in order to allow fabricating PEC thin films, that can be easily peeled off from the support, cut to any size and shape, whose thickness can be controlled by setting reticulation and time and/or chitosan concentration

Fabrication and characterization of micrometer-scale ZnO memristors

2015

Memristors are an interesting class of resistive random access memory (RRAM) based on the electrical switching of metal oxide film resistivity . They are characterized for exhibiting resistive switching between a high-resistance state (HRS) and a low-resistance state (LRS) and have been recently considered as one of the most promising candidates for next-generation nonvolatile memory devices because of their low power consumption, fast switching operation, nondestructive readout, and remarkable scalability. The device structure is simply an oxide layer sandwiched between two metal electrodes. The switching behaviour is dependent both on the oxide material and the choice of metal electrodes.…

Pulsed laser deposition of ZnO and VO2 films for memristor fabrication

2015

Memristors are resistive switching memory devices which have attracted much attention over the last years for high-density memory applications because of their simple structure, small cell size, high speed, low power consumption, potential for 3-D stacking and excellent compatibility with the complementary metal-oxide-semiconductor (CMOS) technology [1]. Beside nonvolatile memory applications, memristors have been also proposed for other different applications including biosensors [2] and neuromorphic [3] circuits. The device structure is simply an oxide material sandwiched between two metal electrodes. The switching behavior is not only dependent on the oxide material but also on the choic…

Fabrication of Electrical Contacts on Pyramid-Shaped NTD-Ge Microcalorimeters Using Free-Standing Shadow Masks

2011

In our effort to fabricate arrays of germanium microcalorimeters for X-ray detection, a truncated square-based pyramid shape has been identified as a suitable geometry for the sensors. It allows to obtain a uniform current spreading across each sensor, and represents a good compromise between having a large support area for the radiation absorber and for maintaining an overall small bolometer volume. This three-dimensional geometry, however, does not allow to create the electrical contacts for the sensors using a regular photoresist-based lift-off metallization process. In this paper we show how to deposit metal contacts on the lateral faces of the pyramidal sensors by metal evaporation thr…

Changes in surface stress, morphology and chemical composition of silica and silicon nitride surfaces during the etching by gaseous HF acid

2007

Abstract HF acid attack of SiO2 and Si3N4 substrates is analyzed to improve the sensitivity of a sensor based on microcantilever. Ex situ analysis of the etching using XPS, SIMS and AFM show significant changes in the anisotropy and the rate of the etching of the oxides on SiO2 and Si3N4 surface. Those differences influence the kinetic evolution of the plastic bending deflection of the cantilever coated with SiO2 and Si3N4 layer, respectively. The linear dependence between the HF concentration and the Si3N4 cantilever bending corresponds to a deep attack of the layer whereas the non-linear behavior observed for SiO2 layer can be explained by a combination of deep and lateral etching. The ca…