Open Access
Silver nanoparticles loaded electrospun nanofibers for humidity optical fiber sensing
(2012) Urrutia Azcona, Aitor; Rivero Fuente, Pedro J.; Goicoechea Fernández, Javier; Rodríguez, Yoany; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
In this work, a new optical device based on silver loaded electrospun nanofibers (ENFs) for measuring Relative Humidity is proposed. Fiber mats composed of poly(acrylic acid) and β-cyclodextrin were deposited onto an optical fiber core by electrospinning. Afterwards the ENFs were submitted to a thermal curing. Then, the ENFs were loaded with Ag nanoparticles (Ag NPs) synthesized using a Ag+ loading step and a further reduction step with dimethylamine borane (DMAB). Several load/reduction cycles were performed. Ag NPs enhance significantly the optical response of the polymer-only fiber mats. The Ag NPs loaded ENF sensor was tested using controlled variations of Relative Humidity (RH). The results showed a very fast response of the absorbance spectra enabling high performance applications such as human breathing monitoring.
Open Access
Humidity sensor based on silver nanopartlcles embedded in a polymeric coating
(Sciendo, 2012) Rivero Fuente, Pedro J.; Urrutia Azcona, Aitor; Goicoechea Fernández, Javier; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería; Ingeniaritza; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC
In this work, it is presented a novel optical fiber humidity sensor based on silver nanoparticle-loaded polymeric coatings built onto an optical fiber core. The polymeric film was fabricated using the Layer-by-Layer assembly technique. The silver nanoparticles (Ag NPs) were characterized using transmission electron microscopy (TEM and UV-VIS spectroscopy. A Localized Surface Plasmon Resonance (LSPR) attenuation band is observed when the thickness of the coating increases, and showed a very good sensitivity to Relative Humidity (RH) variations, suitable for high performance applications such as human breathing monitoring.
Open Access
Continuous liquid-level sensor based on a long-period grating and microwave photonics filtering techniques
(IEEE, 2016) Ricchiuti, Amelia L.; Barrera, D.; Urrutia Azcona, Aitor; Goicoechea Fernández, Javier; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
A fiber optic liquid-level sensor based on a long period grating (LPG) is proposed and experimentally validated. The principle of operation is based on a technique used to analyze microwave photonics filters. A 4-cm-long LPG cascaded with a high-reflectivity fiber Bragg grating is employed to achieve a continuous liquid-level sensor. The measurements have been performed using a modulator and a photo-detector with a modest bandwidth of less than 500 MHz, showing a sensitivity of -12.71 dB/cm and a standard deviation of 0.52 dB. One of the significant advantages of such sensing structure is that it is based on low-bandwidth radio frequency and off-the-shelf photonic components. In addition, the simple proposed scheme presents good repeatable performance and proves to be intrinsically robust against environmental changes, stable, and easy to reconfigure.
Open Access
Generation of lossy mode resonances with different nanocoatings deposited on coverslips
(Optical Society of America, 2020) Fuentes Lorenzo, Omar; Goicoechea Fernández, Javier; Corres Sanz, Jesús María; Del Villar, Ignacio; Ozcariz Celaya, Aritz; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
The generation of lossy mode resonances (LMRs) with a setup based on lateral incidence of light in coverslips is a simple platform that can be used for sensing. Here the versatility of this platform is proved by studying the deposition of different coating materials. The devices were characterized with both SEM and AFM microscopy, as well as ellipsometry, which allowed obtaining the main parameters of the coatings (thickness, refractive index and extinction coefficient) and relating them with the different sensitivities to refractive index attained with each material. In this way it was possible to confirm and complete the basic rules observed with lossy mode resonance based optical fiber sensors towards the design of simpler and more compact applications in domains such as chemical sensors or biosensors.
Open Access
Effect of both protective and reducing agents in the synthesis of multicolor silver nanoparticles
(Springer, 2013) Rivero Fuente, Pedro J.; Goicoechea Fernández, Javier; Urrutia Azcona, Aitor; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, the influence of variable molar ratios between reducing and loading agents (1:100, 1:50, 1:20, 1:10, 1:5, 1:2, 1:1, 2:1) and between protective and loading agents (0.3:1, 0.75:1, 1.5:1, 3:1, 7.5:1, 30:1, 75:1) in the synthesis of silver nanoparticles by chemical reduction has been evaluated to obtain multicolor nanoparticles with a high stability in time. The protective agent poly(acrylic acid, sodium salt) (PAA) and reducing agent dimethylaminoborane (DMAB) play a key role in the formation of the resultant color. Evolution of the optical absorption bands of the silver nanoparticles as a function of PAA and DMAB molar ratios made it possible to confirm the presence of silver nanoparticles or clusters with a specific shape. The results reveal that a wide range of colors (violet, blue, green, brown, yellow, red, orange), sizes (from nanometer to micrometer), and shapes (cubic, rod, triangle, hexagonal, spherical) can be perfectly tuned by means of a fine control of the PAA and DMAB molar concentrations.
Open Access
An antibacterial surface coating composed of PAH/SiO2 nanostructurated films by layer by layer
(Wiley, 2010) Urrutia Azcona, Aitor; Rivero Fuente, Pedro J.; Ruete Ibarrola, Leyre; Goicoechea Fernández, Javier; Fernández Valdivielso, Carlos; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería; Ingeniaritza; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC
In this work we propose a novel antibacterial coating composed of SiO2 and the polymer Poly(allylamine hydrochloride) (PAH). The coating was fabricated by the technique Layer-by-Layer (LbL). This technique has already been used in previous works, and it has the advantage that it allows to control the construction of nanosized and well organized multilayer films. Here, 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. It has been demonstrated these PAH/SiO2 coating films have a very good antimicrobial behaviour against this type of bacteria.
Open Access
Photonic crystal fiber temperature sensor based on quantum dot nanocoatings
(Hindawi / Wiley, 2009) Larrión Zabaleta, Beatriz; Hernáez Sáenz de Zaitigui, Miguel; Arregui San Martín, Francisco Javier; Goicoechea Fernández, Javier; Bravo Larrea, Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Quantum dot nanocoatings have been deposited by means of the Layer-by-Layer technique on the inner holes of Photonic Crystal Fibers (PCFs) for the fabrication of temperature sensors. The optical properties of these sensors including absorbance, intensity emission, wavelength of the emission band, and the full width at half maximum (FWHM) have been experimentally studied for a temperature range from -40 to 70ºC.
Open Access
Sensitivity improvement of a humidity sensor based on silica nanospheres on a long-period fiber grating
(MDPI, 2009) Viegas, Diana; Goicoechea Fernández, Javier; Santos, José Luís; Araújo, Francisco Moita; Ferreira, Luis Alberto; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
This work addresses a new configuration that improves the sensitivity of a humidity sensor based on a long-period fiber grating coated with a SiO(2)-nanospheres film. An intermediate higher refractive index overlay, deposited through Electrostatic Self-Assembly, is placed between the fiber cladding and the humidity sensitive film in order to increase the total effective refractive index of the coating. With this intermediate design, a three-fold improvement in the sensitivity was obtained. Wavelength shifts up to 15 nm against 5 nm were achieved in a humidity range from 20% to 80%.
Open Access
Layer-by-layer nano-assembly: a powerful tool for optical fiber sensing applications
(MDPI, 2019) Rivero Fuente, Pedro J.; Goicoechea Fernández, Javier; Arregui San Martín, Francisco Javier; Ingeniaritza; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC; Ingeniería; Ingeniería Eléctrica, Electrónica y de Comunicación
The ability to tune the composition of nanostructured thin films is a hot topic for the design of functional coatings with advanced properties for sensing applications. The control of the structure at the nanoscale level enables an improvement of intrinsic properties (optical, chemical or physical) in comparison with the traditional bulk materials. In this sense, among all the known nanofabrication techniques, the layer-by-layer (LbL) nano-assembly method is a flexible, easily-scalable and versatile approach which makes possible precise control of the coating thickness, composition and structure. The development of sensitive nanocoatings has shown an exceptional growth in optical fiber sensing applications due to their self-assembling ability with oppositely charged components in order to obtain a multilayer structure. This nanoassembly technique is a powerful tool for the incorporation of a wide variety of species (polyelectrolytes, metal/metal oxide nanoparticles, hybrid particles, luminescent materials, dyes or biomolecules) in the resultant multilayer structure for the design of high-performance optical fiber sensors. In this work we present a review of applications related to optical fiber sensors based on advanced LbL coatings in two related research areas of great interest for the scientific community, namely chemical sensing (pH, gases and volatile organic compounds detection) as well as biological/biochemical sensing (proteins, immunoglobulins, antibodies or DNA detection).
Open Access
Application of active methodologies based on real cases - university-industry collaboration
(IEEE, 2024-08-01) Andueza Unanua, Ángel María; Urrutia Azcona, Aitor; Erro Betrán, María José; Ruiz Zamarreño, Carlos; Leandro González, Daniel; Elosúa Aguado, César; Socorro Leránoz, Abián Bentor; Goicoechea Fernández, Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PINNE2022-UPNA
During the last academic years, the industrial electronics specialties of the Industrial Engineering Bachelor's Degrees of the Public University of Navarra (UPNA) suffered a gradual loss of students. In order to reverse this trend, a teaching innovation project was designed based on the planned use of active learning methodologies in collaboration with Navarra's leading companies in industrial electronics. The project aims to enhance student learning by making teaching more engaging and practical, as well as boost the social visibility of electronics by improving the perception among students of this strategic industrial sector in the region of Navarra.