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.
Open Access
Silicon carbide as a material-based high-impedance surface for enhanced absorption within ultra-thin metallic films
(Optical Society of America, 2020) Pérez Escudero, José Manuel; Buldain, Iban; Beruete Díaz, Miguel; Goicoechea Fernández, Javier; Liberal Olleta, Íñigo; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
The absorption of infrared radiation within ultra-thin metallic films is technologically relevant for different thermal engineering applications and optoelectronic devices, as well as for fundamental research on sub-nanometer and atomically-thin materials. However, the maximal attainable absorption within an ultra-thin metallic film is intrinsically limited by both its geometry and material properties. Here, we demonstrate that material-based high-impedance surfaces enhance the absorptivity of the films, potentially leading to perfect absorption for optimal resistive layers, and a fourfold enhancement for films at deep nanometer scales. Moreover, material-based high-impedance surfaces do not suffer from spatial dispersion and the geometrical restrictions of their metamaterial counterparts. We provide a proof-of-concept experimental demonstration by using titanium nanofilms on top of a silicon carbide substrate.
Open Access
Metallic-dielectric layer based hyperbolic mode resonances in planar waveguides
(IEEE, 2024) González Salgueiro, Lázaro José; Del Villar, Ignacio; Corres Sanz, Jesús María; Goicoechea Fernández, Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this research article, we present a comprehensive investigation into the integration of dielectric and metallic layers on optical waveguides, specifically targeting sensing applications. By utilizing a single bilayer of metal and dielectric on a planar waveguide that meets the conditions of a hyperbolic metamaterial, we significantly enhance the visibility of lossy mode resonances generated with a single dielectric layer, in what can be considered as a hyperbolic mode resonance (HMR), without compromising sensitivity. This improvement leads to an enhanced figure of merit and a reduction of the signal-to-noise ratio. Real-time evolution of spectra during the dielectric layer deposition allows us to establish a map of the multiple phenomena involved, such as surface plasmon resonance, lossy mode resonance, and mode transition. Combining these phenomena in a single structure leads to an unprecedented enhancement in sensing capabilities, demonstrating the potential of dielectric-metallic layer integration on optical waveguides for advanced sensing applications. Moreover, the optimized sensing performance offers promising opportunities for on-chip sensing devices and various applications in biomedicine, environmental monitoring, and chemical analysis.
Open Access
Self-referenced optical fiber sensor based on LSPR generated by gold and silver nanoparticles embedded in layer-by-layer nanostructured coatings
(MDPI, 2022) Martínez Hernández, María Elena; Goicoechea Fernández, Javier; Rivero Fuente, Pedro J.; Sandúa Fernández, Xabier; Arregui San Martín, Francisco Javier; Ingeniaritza; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería; Ingeniería Eléctrica, Electrónica y de Comunicación
In this work, an optical fiber sensor based on the localized surface plasmon resonance (LSPR) phenomenon has been designed for the detection of two different chemical species (mercury and hydrogen peroxide) by using Layer-by-Layer Embedding (LbL-E) as a nanofabrication technique. In the first step, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) have been synthesized by using a chemical protocol as a function of the strict control of three main parameters, which were polyelectrolyte concentration, a loading agent, and a reducing agent. In the second step, their incorporation into nanometric thin films have been demonstrated as a function of the number of bilayers, which shows two well-located absorption peaks associated to their LSPR in the visible region at 420 nm (AgNPs) and 530 nm (AuNPs). Finally, both plasmonic peaks provide a stable real-time reference measurement, which can be extracted from the spectral response of the optical fiber sensor, which shows a specific sensing mechanism as a function of the analyte of study.
Open Access
An optical fiber sensor for Hg2+ detection based on the LSPR of silver and gold nanoparticles embedded in a polymeric matrix as an effective sensing material
(MDPI, 2021-07-07) Martínez Hernández, María Elena; Sandúa Fernández, Xabier; Rivero Fuente, Pedro J.; Goicoechea Fernández, Javier; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work, an optical fiber sensor based on the localized surface plasmon resonance (LSPR) phenomenon is presented as a powerful tool for the detection of heavy metals (Hg2+). The resultant sensing film was fabricated using a nanofabrication process, known as layer-by-layer embedding (LbL-E) deposition technique. In this sense, both silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized using a synthetic chemical protocol as a function of a strict control of three main parameters: polyelectrolyte concentration, loading agent, and reducing agent. The use of metallic nanostructures as sensing materials is of great interest because well-located absorption peaks associated with their LSPR are obtained at 420 nm (AgNPs) and 530 nm (AuNPs). Both plasmonic peaks provide a stable real-time reference that can be extracted from the spectral response of the optical fiber sensor, giving a reliable monitoring of the Hg2+ concentration.
Open Access
Addressing the impact of surface roughness on epsilon-near-zero silicon carbide substrates
(American Chemical Society, 2023) Navajas Hernández, David; Pérez Escudero, José Manuel; Martínez Hernández, María Elena; Goicoechea Fernández, Javier; Liberal Olleta, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Epsilon-near-zero (ENZ) media have been very actively investigated due to their unconventional wave phenomena and strengthened nonlinear response. However, the technological impact of ENZ media will be determined by the quality of realistic ENZ materials, including material loss and surface roughness. Here, we provide a comprehensive experimental study of the impact of surface roughness on ENZ substrates. Using silicon carbide (SiC) substrates with artificially induced roughness, we analyze samples whose roughness ranges from a few to hundreds of nanometer size scales. It is concluded that ENZ substrates with roughness in the few nanometer scale are negatively affected by coupling to longitudinal phonons and strong ENZ fields normal to the surface. On the other hand, when the roughness is in the hundreds of nanometers scale, the ENZ band is found to be more robust than dielectric and surface phonon polariton (SPhP) bands.
Open Access
Building global competencies: a strategic approach to internationalization of engineering education
(Eindhoven University of Technology and Fontys University of Applied Sciences, 2023) Berrueta Irigoyen, Alberto; Samanes Pascual, Javier; Parra Laita, Íñigo de la; Goicoechea Fernández, Javier; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
International mobility is an essential aspect of undergraduate education that enables students to acquire the necessary competences required by the European Higher Education Area (EHEA). However, small universities such as the Public University of Navarre (UPNA), which has approximately 9,000 bachelor's students, face challenges in providing effective mobility opportunities. The most significant hurdles include offering attractive mobility experiences to students and establishing mobility agreements with other universities. Nonetheless, the reduced size of UPNA provides some potential benefits, such as more personalized advice for students and better knowledge of the available destinations. This article discusses the internationalization strategy implemented by the Faculty of Industrial and ICT Engineering at UPNA, which has enabled over 25% of its students to participate in a mobility experience, resulting in a high satisfaction rate. This contribution provides valuable insights into how smaller universities can successfully offer international mobility programmes to their students.
Open Access
In situ synthesis of gold nanoparticles in layer-b y-layer polymeric coatings for the fabrication of optical fiber sensors
(MDPI, 2022) Martínez Hernández, María Elena; Goicoechea Fernández, Javier; Rivero Fuente, Pedro J.; Arregui San Martín, Francisco Javier; Ingeniaritza; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería; Ingeniería Eléctrica, Electrónica y de Comunicación
A new method is proposed to tune the interferometric response of wavelength-based optical fiber sensors. Using the nanoparticle in situ synthesis (ISS) technique, it is possible to synthesize gold nanoparticles (AuNPs) within a pre-existing polymeric thin film deposited at the end-face of an optical fiber. This post-process technique allows us to adjust the optical response of the device. The effect of the progressive synthesis of AuNPs upon polymeric film contributed to a remarkable optical contrast enhancement and a very high tuning capability of the reflection spectra in the visible and near-infrared region. The spectral response of the sensor to relative humidity (RH) variations was studied as a proof of concept. These results suggest that the ISS technique can be a useful tool for fiber optic sensor manufacturing.
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
Enhancing engineering competencies curricula in the context of university-industry chairs
(IEEE, 2023) Sanchis Gúrpide, Pablo; San Martín Biurrun, Idoia; Berrueta Irigoyen, Alberto; Samanes Pascual, Javier; Parra Laita, Íñigo de la; Ursúa Rubio, Alfredo; Astrain Ulibarrena, David; Goicoechea Fernández, Javier; Institute of Smart Cities - ISC
University-industry Chairs can play a key role to enhance the acquisition of certain curricular competencies of the Engineering Degrees such as teamwork capability, oral and written communication skills, entrepreneurship initiative and industrial environment knowledge, all of them highly valued and long demanded by the industrial companies. This paper describes the organizational framework and the main programs of the Chair of Renewable Energies of the Public University of Navarre and evaluates how it is contributing effectively to improving the acquisition of these competencies and skills.