Suchergebnisse

The paper presents the main results of a previously developed methodology to better evaluate new technologies in Smart Cities, using a tool to evaluate different systems and technologies regarding their usefulness, considering each application and how technologies can impact the physical space and natural environment. Technologies have also been evaluated according to how they are used by citizens, who must be the main concern of all urban development. Through a survey conducted among the Smart City Spanish network (RECI) we found that the ICT's that change our cities everyday must be reviewed, developing an innovative methodology in order to find an analysis matrix to assess and score all the technologies that affect a Smart City strategy. The paper provides the results of this methodology regarding the three main aspects to be considered in urban developments: mobility, energy efficiency, and quality of life after obtaining the final score for every analyzed technology. This methodology fulfills an identified need to study how new technologies could affect urban scenarios before being applied, developing an analysis system to be used by urban planners and policy-makers to decide how best to use them, and this paper tries to show, in a simple way, how they can appreciate the variances between different solutions. ; The authors would like to acknowledge Spanish Ministry of Economy and Competitiveness for the financial support through TEC2016-78047-R and Government of Navarra (Spain) Research Grants.

During the last decades, both governments and companies have been committed to the continuous checking of biological parameters, which can prevent extra costs to administrations. A very efficient way to address this issue is by designing biosensors. This contribution reviews the advances made using optical fibre technology, which have lately agglutinated much of the scientific interest related to the development of biosensors. However, the wide number of publications describing the use of optical fibre for detecting biomarkers has probably blurred the main goal: obtaining portable, simple, easy-to-handle and cost-effective biosensors. With this purpose, this contribution presents some optical fibre structures which have been analysed in terms of several optical parameters of interest from a photonics point of view: sensitivity, quality factor, full width at half minimum, limit of detection and figure of merit. This has made it possible to classify the most advanced optical fibre sensing techniques and, hence, their suitability when developing biosensing applications. ; This work was supported by the Regional Government of Navarra, Spain (projects with references 72/2015 and PC021-022) and by the Agencia Estatal de Investigación (Spanish National Research Agency) through the project with reference TEC2016-78047-R.

The deposition of an indium oxide (In2O3) thin film on conventional planar waveguides (a coverslip and a glass slide) allows generating lossy mode resonances (LMR) by lateral incidence of light on the waveguide and by registering the optical spectrum in a spectrometer. This novel sensing system becomes an alternative to optical fibre, the substrate where LMR-based sensors have been developed so far, since it is easier to handle and more robust. An additional advantage is that cost effective waveguides, such as slides or coverslips, can be used in a platform that resembles surface plasmon resonance-based sensors in the Kretschmann configuration but without the need for a coupling prism and with the advantage of being able to generate TE and TM LMR resonances with metallic oxide or polymer thin films. The results are corroborated with simulations, which provide in-depth understanding of the phenomena involved in the sensing system. As a proof-of-concept for the optical platform, two refractometers were developed, one with low sensitivity and for a wide range of refractive indices, and the other with higher sensitivity but for a narrower refractive index range. The sensors presented here open up the path for the development of LMR-based chemical sensors, environmental sensors, biosensors, or even the generation of other optical phenomena with the deposition of multilayer structures, gratings or nanostructures, which is much easier in a planar waveguide than in an optical fibre. ; The authors would like to acknowledge the partial support to the Spanish Ministry of Economy and Competitiveness TEC2016-78047-R and TEC2016-79367-C2-2-R research funds, the pre-doctoral research grant and the Government of Navarre 2018/PC021-022 OPTISENS research funds.

Here, we present a novel method to fabricate long period gratings using standard single mode optical fibers (SMF). These optical devices were fabricated in a three-step process, which consisted of etching the SMF, then coating it with a thin-film and, the final step, which involved removing sections of the coating periodically by laser ablation. Tin dioxide was chosen as the material for this study and it was sputtered using a pulsed DC sputtering system. Theoretical simulations were performed in order to select the appropriate parameters for the experiments. The responses of two different devices to different external refractive indices was studied, and the maximum sensitivity obtained was 6430 nm/RIU for external refractive indices ranging from 1.37 to 1.39. ; This work was supported by the Spanish Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) (TEC2016-78047-R and TEC2016-79367-C2-2-R), and by the Government of Navarre through the project with reference 2017/PI044.

The use of Vehicular Ad-Hoc Networks (VANETs) is growing nowadays and it includes both roadside-to-vehicle communication (RVC) and inter-vehicle communication (IVC). The purpose of VANETs is to exchange useful information between vehicles and the roadside infrastructures for making an intelligent use of them. There are several possible applications for this technology like: emergency warning system for vehicles, cooperative adaptive cruise control or collision avoidance, among others. The objective of this work is to develop a VANET prototype system for urban environments using IEEE 802.15.4 compliant devices. Simulation-based values of the estimated signal strength and radio link quality values are obtained and compared with measurements in outdoor conditions to validate an implemented VANET system. The results confirm the possibility of implementing low cost vehicular communication networks operating at moderate vehicular speeds. ; This work has been supported by following projects Ref. IIM010566. RI1 from the Government of Navarre, Industry Department and the Ministry of Economy and Competitiveness of Spain through project TEC2010-17805.

There exists an increasing interest in monitoring low concentrations of biochemical species, as they allow the early-stage detection of illnesses or the monitoring of the environment quality. Thus, both companies and research groups are focused on the development of accurate, fast and highly sensitive biosensors. Optical fiber sensors have been widely employed for these purposes because they provide several advantages for their use in point-of-care and real-time applications. In particular, this review is focused on optical fiber biosensors based on luminescence and absorption. Apart from the key parameters that determine the performance of a sensor (limit of detection, sensibility, cross-sensibility, etc.), other features are analyzed, such as the optical fiber dimensions, the sensing set ups and the fiber functionalization. The aim of this review is to have a comprehensive insight of the different aspects that must be taken into account when working with this kind of sensors. ; This research was funded by the Spanish AGENCIA ESTATAL DE INVESTIGACIÓN (AEI), through the project with reference PID2019-106231RB-I00—ESPADA and also by the Regional Government of Navarra, through the project with reference 0011-1365-2020-000061–BREATHALYSER (FEDER).

Two phenomena for enhancing the sensitivity of longperiod fiber gratings are combined toward an increase of the sensitivity to strain of this type of devices: the dispersion turning point (DTP) and the cladding diameter reduction by an etching process. The results prove that sensitivities up to 20 pm/με can be attained, which is a ten-fold improvement compared to the previous works. The sensitivity in the grating region, which is subjected to etching, does not depend on the order of the cladding mode responsible for the attenuation bands generated in the transmission spectrum, but on the proximity to the DTP for each mode order. On the other hand, the sensitivity to strain of the global structure, including the region without etching, can be increased for lower order modes in a perceptible way if the length of the etched region is smaller compared to the fiber region under stress. The experimental results are supported with simulations based on coupled-mode theory and on FIMMWAVE, which allows understanding the phenomena involved during the sensing process. ; This work was supported in part by the Spanish Ministry of Economy and Competitiveness (TEC2016-78047-R – AEI/FEDER, UE), in part by the Government of Navarra PI044 NANOSEN, and in part by the Pinar del Río University.

The application of an etching process in a single-mode multimode single-mode (SMS) fiber allows monitoring the change of refractive index of wind turbine gearbox oil due to temperature and degradation with a limitation at short temperatures, where the transmission and attenuation bands in the optical spectrum fade. The application of a black tin oxide nanocoating solves this issue and allows tuning the refractive index region where the sensitivity is maximum. The SMS was designed for operating at short wavelengths, where the setup is less expensive. The experimental results were contrasted with a theoretical analysis developed with FIMMWAVE, which allowed understanding better the phenomena involved in the experiments. ; This work was supported in part by the Spanish Ministry of Education and Science-FEDER TEC 2016-78047 and in part by the Government of Navarre through its project with reference 2017/PI044.

Nanocoated D-shaped optical fibers have been proven as effective sensors. Here, we show that the full width at half minimum (FWHM) of lossy mode resonance can be reduced by optimizing the nanocoating width, thickness and refractive index. As a counterpart, several resonances are observed in the optical spectrum for specific conditions. These resonances are caused by multiple modes guided in the nanocoating. By optimizing the width of the coating and the imaginary part of its refractive index, it is possible to isolate one of these resonances, which allows one to reduce the full width at half minimum of the device and, hence, to increase the figure of merit. Moreover, it is even possible to avoid the need of a polarizer by designing a device where the resonance bands for TE and TM polarization are centered at the same wavelength. This is interesting for the development of optical filters and sensors with a high figure of merit. ; Spanish Ministry of Education and Science-FEDER (TEC2013-43679-R, TEC2016-78047- R); Government of Navarra Health Department (64/2015, 72/2015); Government of Navarra 2016/PI008.

Thin-film coated single-mode–multimode–single-mode (SMS) structures have been analyzed both theoretically and experimentally with the aim of detecting different refractive indices. By adequate selection of the thickness of the thin film and of the diameter of the multimode segment in the SMS structure, a seven-fold improvement can be obtained in the sensitivity of the device to the surrounding medium refractive index, achieving a maximum sensitivity of 1199.18 nm∕refractive index unit for the range of refractive indices from 1.321 to 1.382. Using layer-by-layer self-assembly for deposition, both on the cladding and on the tip of the multimode segment, allows the reflected power to increase, which avoids the application of a mirror on the tip of the multimode segment. ; This work was supported in part by the Spanish Ministry of Education and Science-FEDER TEC2010-17805 and Government of Navarra research grants.

By coating a single-mode–multimode–single-mode (SMS) structure with a high refractive index thin-film it is possible to obtain a transition of modes for specific combinations of thin-film thickness, thinfilm refractive index and surrounding medium refractive index, which permits to develop devices with a high sensitivity to specific parameters. In order to gain a better knowledge of the phenomenon the experimental results are corroborated numerically with the Transfer-Matrix-Method. The influence of losses in the thin-film has also been studied. The results obtained prove that a thin-film coated SMS structure is a simple and costeffective platform for development of sensors and optical filters. ; This work was supported by the Spanish Ministry of Education and Science-FEDER TEC2010-17805 and Government of Navarra research grants.

In this work, optical fiber refractometers based on the successive incorporation of gold nanoparticles have been fabricated by means of the Layer-by-Layer Embedding (LbL-E) deposition technique. This enables the apparition of two different optical phenomena, Localized Surface Plasmon Resonance (LSPR) and Lossy Mode Resonance (LMR). The absorption peaks related to both phenomena were captured during the fabrication process, showing a different evolution as a function of the resultant thickness coating. Initially, LSPR band is observed for thinner coatings, whereas multi-LMR bands are observed as the thickness coating is increased. In addition, the response of both phenomena to variations of the surrounding medium refractive index (SMRI) was monitored, studying their different sensitivities. LSPR band only shows intensity variation with negligible wavelength displacement whereas LMR bands present a strong wavelength response. The combination of both resonances opens the door in the design of self-referenced optical devices for sensing applications. ; This work was supported by the Spanish Economy and Competitiveness Ministry-Feder TEC2013-43679-R and by the Government of Navarra research grants.

This contribution shows the monitoring of AC and DC millivoltage signals by means of lossy mode resonances generated by Indium Tin Oxide (ITO) on optical fibers. Sensors were obtained by sputtering ITO thin-films onto 25 mm-length segments of 200 μm bare optical fibers. Depositing a 1 μm thin-film of ITO leads to obtain reduced thin-film resistances of near 340 ohms. This allows the detection of voltage signals by monitoring the wavelength shift of the resonances. Sensitivities up to 40 nm/V can be achieved when tracking sinusoidal signals of a few cents of mV peak-to-peak. This opens the path for further research pursuing the detection of biomedical signals. ; This work has been supported by the Spanish National Research Agency through the project with reference TEC2016-78047-R, by the OPTISENS Government of Navarra Research Project and by a predoctoral research grant of the Public University of Navarra.

Póster presentado a las 10th Trends in Nanotechnology – TNT 09. Barcelona, 2009. ; In this article we propose a novel antibacterial coating composed of SiO2 and the polymer Poly(allylamine hydrochloride) (PAH) on glass slides by the technique Layer-by- Layer (LbL)1. This technique has already used in previous works, and it has the advantage that it allows to control the construction of nanosized and well organized multilayer films. In this work, the new nanotexturized LbL SiO2 surface acts as antibacterial agent. The fabricated coatings have been tested in bacterial cultures of genus Lactobacillus to observe their antibacterial properties. ; This work was funded in part by the Spanish Ministry of Education and Science-FEDER TEC2006-12170/MIC Research Grant and Government of Navarre-FEDER Euroinnova Research Grants

The development of an optical fiber refractometer by hydrogen fluoride etching and sputtering deposition of a thin-film of indium tin oxide on a single-mode-multimode-single-mode fiber structure has been analyzed with the aim of improving the sensitivity to the changes of the refractive index (RI) of the external medium. The device is sensitive to the RI changes of the surrounding medium, which can be monitored by tracking the spectral changes of an attenuation band or with a fast Fourier transform (FFT) analysis. By using an optical spectrum analyzer combined with a simple FFT measurement technique, the simultaneous real time monitoring is achieved. The results show that the sensitivity depends on the thin-film thickness. A maximum of 1442 nm/RIU (refractive index unit) in the 1.32–1.35RIUrange has been attained. In addition, a theoretical analysis has been performed, where simu lationsmatched with the experimental results. As a practical appli cation of the developed optical fiber structure, a °Brix (°Bx) sensor has been implemented with a sensitivity of 2.13 nm/°Bx and 0.25 rad/°Bx respectively for wavelength and phase shift detection. ; This work was supported in part by the Agencia Estatal de Investigacion, in part by Fondo Europeo de Desarrollo Regional (TEC2016-78047-R), in part by the Government of Navarre through its projects with references: 2016/PI008, 2016/PC025, and 2016/PC026, and in part by the Colombian Administrative Department of Science, Technology and Innovation—Colciencias, through the Program for national doctorates, calling 617 of 2013.