Comunicaciones y ponencias de congresos ISC - ISC biltzarretako komunikazioak eta txostenak
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Publication Open Access On the impact of high-power grid-connected thyristor rectifiers on the efficiency of hydrogen electrolyzers(IEEE, 2024-08-30) Iribarren Zabalegui, Álvaro; Barrios Rípodas, Ernesto; Rivera, Marco; Wheeler, Patrick; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaThis paper investigates the impact of power supply and dc current ripple on the efficiency of water electrolyzers and demonstrates that optimally sized thyristor rectifiers meeting grid power quality regulations can effectively supply high-power electrolyzers with minimal impact on electrolyzer efficiency. Firstly, an equivalent electrical model for the electrolyzer is developed, and the efficiency reduction caused by dc current ripple is analyzed. This is validated by means of experimental data from a 5-kW alkaline electrolyzer operated with both thyristor- and IGBT-based rectifiers. Next, the paper explores the operation of high-power electrolyzers supplied by 6- and 12-pulse thyristor rectifiers complying with grid power quality standards. Results show that with optimal sizing of ac-side source voltage and filtering inductances, these solutions exhibit negligible dc current ripple impact on electrolyzer efficiency. These findings, validated through simulation of a 5.5 MW electrolyzer, highlight the viability of thyristor rectifiers in high-power electrolysis applications, and emphasize the importance of an optimal power supply design and sizing for enhancing water electrolyzers' performance.Publication Open Access Is time more important than distance to optimize freight delivery routes? An approach using the value of time(Elsevier, 2024-02-23) Alvarez Indave, Pablo; Serrano Hernández, Adrián; Lerga Valencia, Iosu; Faulín Fajardo, Javier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA26-2022Traditional approaches to optimize freight delivery routes are based on minimizing a distance-based cost function. New approaches use also time as the objective function to minimize. However, the trade-off between time and distance is sometimes unclear. This paper presents a new approach to optimize delivery routes in which both time and distance are used together to optimize delivery routes. For this purpose, the operating cost of a vehicle and the value of time have been used to convert time and distance into monetary units. Through the study of three different networks in Spain with different level of detail (the region of Catalonia, the city of Barcelona, and the old part of Pamplona), the results have indicated that minimizing both time and distance provides better results than the traditional approach, especially at a local level where congestion effects are more relevant.Publication Open Access Evaluation of mutual coupling between slots in a metasurface enhanced SIW slotted antenna(IEEE, 2023-10-26) Chocarro Álvarez, Javier; Ederra Urzainqui, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCIn this paper, we explore the conductance properties of a longitudinal slot on a substrate integrated waveguide (SIW) with three different models. These models allow us to evaluate the impact on the slot conductance of covering it with a metasurface to improve the radiation performance. In particular, the influence of the MTS on the coupling between slots will be analyzed. Our results show that the presence of the MTS reduces the slot conductance and slot resonance length, but has limited impact on the coupling.Publication 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 PublikoaIn 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.Publication Open Access Nanoparticle derived suppressed-scattering bands for radiative cooling(IEEE, 2023) Lezaun Capdevila, Carlos; Pérez Escudero, José Manuel; Torres García, Alicia E.; Caggiano, Antonio; Peralta, Ignacio; Dolado, Jorge S.; Liberal Olleta, Íñigo; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCLight scattering using resonant nanoparticles is crucial for improving sun irradiance reflection in a daytime radiative cooler. Popular nanoparticles in radiative cooling literature are analyzed in terms of scattering performance due to material dispersion. Different scattering properties in the infrared range have been detected while a similar behavior can be achieved in the solar range due to changes in material dispersion. Also, suppressed scattering windows are produced by dispersive nanoparticles, allowing high reflectance while enabling thermal emission selectively. Material dispersion alone produces such scattering windows, thus, given a material, they will always remain in the same region regardless geometry and location of particles. Lastly, calcium silicate hydrate (CSH), the main phase of concrete, is studied as a dispersive host example. These results demonstrate the importance of a co-design between host and nanoparticles dispersion for daytime radiative cooling and that nanoporosities design are a key ingredient that could allow concrete-based daytime radiative coolers.Publication Open Access Assessment of mm-wave high resolution inverse SAR imaging both with compact and sparse data(IEEE, 2023) Iqbal, Muhammad Amjad; Anghel, Andrei; Datcu, Datcu; Ederra Urzainqui, Íñigo; Iriarte Galarregui, Juan Carlos; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCInverse synthetic aperture radar (ISAR) provides images of objects that are rotated with respect to the radar. An efficient image-focusing algorithm is required to generate ISAR images from the echoes of the raw data. In this study, a monostatic model was deployed to collect radar backscattering data in the millimeter (mm) wave band (67-110 GHz) using targets with circular, rectangular, and non-canonical shapes. The ISAR experiments were performed to assess the imaging performance of the three methods. The ISAR image reconstruction implemented in the wave-number (¿ - k) domain solves the target reflectivity and allows the target to be close to the radar. This shows that the mm-wave radar can achieve a sufficient resolution in the range and azimuth dimensions. Finally, we compared the results with those of spherical wavefront compensation (SWFC) and back-projection (BP) methods. The efficiencies of the three methods were tested using compressible data with wavelet-decomposition-based sparse measurements. To demonstrate the performance of the given methods, the point spread function (PSF) for the impulse response of the mm-wave wire was computed. There is a trade-off: the ¿ - k domain loses resolution compared to the SWFC and BP methods but can obtain a satisfactory image at a lower computational cost.Publication Open Access Biophotonic platform for detection of hallmarks of Alzheimer's disease via combined microfluidics and nanofunctionalized fiber sensors(IEEE, 2023) Santano Rivero, Desiree; Lijiao, Zu; Jiwei, Xie; Peng, Liu; Zhang, Xuejun; Shi, Lei; Socorro Leránoz, Abián Bentor; Matías Maestro, Ignacio; Giannetti, Ambra; Baldini, Francesco; Santamaría Martínez, Enrique; Fernández Irigoyen, Joaquín; Li, Kaiwei; Bi, Wei; Van den Hove, Daniel L. A.; Del Villar, Ignacio; Guo, Tuan; Chiavaioli, Francesco; Ciencias de la Salud; Osasun Zientziak; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThe emergence of Covid-19 pandemic has drawn large attention to vulnerable people affected by major diseases. According to the World Health Organization (WHO), more than 55 million people worldwide suffer from dementia. Alzheimer's disease (AD) is the predominant type of dementia, accounting for 60-70% of cases [1]. A long-standing challenge is to attain early diagnosis of AD hallmarks (tau protein, ¿P; amyloid beta, A¿) by detecting them in biological fluids, thus avoiding the labor of specialized hospital personnel and the high cost of imaging examinations. Different biological fluids are being used to detect AD biomarkers, such as cerebrospinal fluid (CSF), serum, blood-plasma [2]. Biomarker level in CSF has been shown to increase in the very early stages of the disease where its elevated value makes higher the risk of a quicker development of AD dementia. Traditional methods for biomarker detection are mostly based on ELISA or mass spectrometry, which possess well-known disadvantages in comparison with electrochemical or optical approaches [3,4].Publication Open Access Ramp-rate control in large PV plants: battery vs. short-term forecast(IEEE, 2018) Marcos Álvarez, Javier; Parra Laita, Íñigo de la; Cirés Buey, Eulalia; Wang, Guang Chao; García Solano, Miguel; Marroyo Palomo, Luis; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThe changeability in the power produced by utility-scale PV plants caused by shadows due to passing clouds can compromise grid stability. Traditionally, some kind of energy storage systems (ESS) is proposed as the solution to reduce power variations below the limits imposed by new grid codes regulations. However, recent short-term forecast sources open the door to control the variability without batteries, using only inverter limitation. This option entails some energy curtailment losses that has not been yet addressed. This paper quantifies these losses for the first time using a meaningful database of 5 s one year data for a 38.5 MW PV plant in a perfect forecast scenery. Finally, we compare the economic cost of installing a lithium-ion battery vs. the inverter limitation solution. The results obtained indicate that battery-less strategies must not be neglected for ramp-rate control, since they can be more cost-effective using perfect forecast for any ramp value.Publication Open Access Short pulse generation in erbium-doped fiber lasers using graphene oxide as a saturable absorber(Science and Technology Publications, Lda., 2023) Monteiro, Catarina S.; Pérez Herrera, Rosa Ana; Silva, Susana; Frazão, Orlando; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThe use of graphene oxide (GO) as a saturable absorber for short pulses generation in an Erbium-doped fiber laser was studied and demonstrated. The saturable absorber consisted of a thin GO film, with a high concentration of monolayer GO flakes, spray-coated on the end face of a ferrule-connected fiber. By including the saturable absorber in the laser cavity and controlling the intra-cavity polarization, the generation of short-pulsed light was achieved under mode-locking and Q-switching operations. Under mode-locking operation, it was observed a pulse train with a fundamental repetition rate of 1.48 MHz, with a working wavelength centered at 1564.4 nm. In the Q-switch operation, a pulse train with a 12.7 kHz repetition rate and a 14.3 µs pulse duration was attained for a 230-mA pump current. Further investigation showed a linear dependence of the repetition rate with the pump power, attaining frequencies between 12.7 and 14.4 kHz.Publication Open Access Experimental evaluation of the safety performance of lithium-ion batteries based on abuse areas(IEEE, 2024) Lalinde Sainz, Iñaki; Berrueta Irigoyen, Alberto; Valera, Juan José; Arza, Joseba; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako GobernuaSafety issues associated with lithium-ion batteries (LIBs) jeopardize their widespread adoption in both stationary applications and electric vehicles. One of the factors that can most affect the safety of a LIB is its chemistry. For this reason, this article aims to evaluate the safety of the two main current chemistries, LFP and NMC. In particular, the safety of both technologies is examined from the perspective of the areas of abuse that characterize their behavior beyond the safe operation area. A commercial 5 Ah pouch cell with LFP chemistry is subjected to various overtemperature and overcharge abuses at different conditions. The results obtained for LFP chemistry cell are discussed together with those for NMC cell from a previous work of the authors. Identification of the abuse areas allows for a comparative analysis of the safety of both chemistries, providing a valuable tool for classifying the abuse behavior of LIBs.Publication Open Access 3D-RL MIMO capacity estimations under vegetation blockage(IEEE, 2023-09-07) Rodriguez Corbo, Fidel Alejandro; Celaya Echarri, Mikel; Shubair, Raed M.; Falcone Lanas, Francisco; Azpilicueta Fernández de las Heras, Leyre; Institute of Smart Cities - ISCMultiplexing gains are one of the many promises for increasing throughput in multiple-input-multiple-output (MIMO) systems. In this sense, a rich scattered environment may be beneficial for the multiplexing capabilities of the MIMO channel. However, mm Wave frequency bands tend to have less effective multipath contributions than sub-6 GHz bands. In this work, an in-deep analysis of the multiplexing capabilities in a mm Wave vehicular-to-infrastructure (V2I) channel is performed. Metrics that may impact the channel capacity like received power and angle-of-arrival (AoA) Spread are fully analyzed as well.Publication Open Access Surface roughness effects on ENZ media IR spectra(IEEE, 2023-09-04) Navajas Hernández, David; Pérez Escudero, José Manuel; Liberal Olleta, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThe development of high-performance nanophotonic technologies faces challenges like material losses and surface roughness. While surface roughness has been studied in the plasmonic regime, its effect on epsilon-near-zero (ENZ) media has been less explored. Two theoretical scenarios arise regarding roughness in ENZ media: one predicts the excitation of a strong longitudinal electric field, while the other suggests minimal changes in reflection due to the large effective wavelength. This study investigates silicon carbide (SiC) as an ENZ substrate, using deep reactive ion etching (DRIE) to create significant surface roughness. The findings show that surface roughness affects the reflection spectra, induces polaritonic effects, and highlights the robustness of SiC against surface roughness. Numerical simulations and experimental measurements confirm these results, revealing that ENZ substrates maintain their reflective properties even with surface roughness on the scale of hundreds of nanometers.Publication Open Access Integrated lithium-ion battery model and experimental validation of a second-life prototype(IEEE, 2023-08-31) Pérez Ibarrola, Ane; San Martín Biurrun, Idoia; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako GobernuaA battery model predicts the battery performance, which can be a useful tool for optimizing battery design and preventing unsafe operation. This becomes especially significant in second-life batteries where the cells have already endured degradation and predicting the lifetime becomes challenging. The assessment of physical phenomena is often performed individually, but the overall battery behavior depends on their interaction. For this purpose, an integrated battery model is developed. Equivalent electric circuits are interconnected to represent the electrochemical reactions, thermodynamic phenomena, and heat transfer mechanisms of the battery. To consider cell degradation, calendar and cycling aging were represented using a semi-empirical model. A battery management system is included to oversee and remain within the safe limits of battery voltage, temperature, and current. Additionally, a passive cell balancing distributes charge evenly. The integrated model is applied to a second-life battery prototype with a nominal capacity and power of 45 Ah and 4 kW, respectively. Its performance is validated with constant current and power cycles, as well as in a microgrid with photovoltaic generation under a self-consumption profile. The model accurately reproduces experimental results of battery power, voltage, temperature, and state of charge.Publication Open Access Modeling a grid-forming DFIG wind turbine(IEEE, 2023-08-31) Oraa Iribarren, Iker; Samanes Pascual, Javier; López Taberna, Jesús; Gubía Villabona, Eugenio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaThis paper presents a small-signal state-space model that allows analyzing the dynamics of doubly-fed induction generator (DFIG)-based wind turbines in which grid-forming control strategies are implemented. Specifically, in this paper, a droop-controlled DFIG wind turbine is modeled. The system is modeled in the dq-axis, synchronized with the grid voltage, which simplifies the modeling by not having to linearize the terms dependent on the rotational speed of the dq-axis. Independent models for each element of the system are obtained, which are then combined to model the complete system under study. This modeling methodology provides great flexibility, allowing for easy inclusion of the LC harmonic filter, and enabling future incorporation of the grid-side converter to analyze its interaction with the rotor-side converter. The developed model is validated through simulation, demonstrating that it accurately reproduces the dynamic response of the system under study.Publication Open Access Integrating simulation and optimization: a case study in Pamplona for self-collection delivery points network design(Cal-Tek, 2023) Izco Berastegui, Irene; Serrano Hernández, Adrián; Sawik, Bartosz; Faulín Fajardo, Javier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA26-2022The disruptions experienced by the processes in the last mile delivery during the SARS-CoV-2 pandemic raised the dilemma of up-to-date last mile approaches for Urban Logistics (UL) issues. Self-Collection Delivery Systems (SCDS) have been proved to be an improvement for all the players of the SC, providing flexibility of time-windows and reducing overall mileage, delivery time and, consequently, gas emissions. Differing from previous works involving hybrid modeling for automated parcel lockers (APL) network design, this paper brings a System Dynamics Simulation Model (SDSM) to forecast online shopping demand in the Spanish city of Pamplona. A bi-criteria Facility Location Problem (FLP) is solved by means of an e-constraint method, where e is defined as the level of coverage of the total demand. The experiment run considers 90% of demand coverage, in order to obtain the most complex network possible. The simulation and demand forecast was carried out using Anylogic simulation software and the optimization procedure makes use of the Java-based CPLEX API solver.Publication Open Access High-dynamics P-E and Q-f control of PV inverters for strong and weak grids(IEEE, 2023-08-31) Urtasun Salinas, Ibai; Urtasun Erburu, Andoni; Marroyo Palomo, Luis; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThe increase of power electronic-based generators is causing the replacement of synchronous generators, which poses new challenges to electrical grid stability. In particular, when grid-following inverters are connected to weak grids, stability problems related to the PLL used for synchronization arise. To address this issue, grid-forming controls are widely proposed. However, the conventional implementations, such as droop control or virtual synchronous generator, lead to slow power controls, which are not suitable for photovoltaic systems with no storage. Thus, to improve the control dynamics, this paper proposes a new P-E and Q-f control. This control uses the reactive power for grid synchronization, avoiding the use of a PLL, and is valid for both inductive and resistive lines. Furthermore, thanks to the controller design developed in the paper, the control remains rapid and stable for very weak grids. Simulation results validates the control design and shows that the proposed control is much faster than the droop control for all types of grids.Publication Open Access High-performance terahertz optoelectronic receivers enabled by monolithic integration of SBDs and UTC-PDs: modelling and design(IEEE, 2023-10-31) Belío Apaolaza, Íñigo; Seddon, James; Pérez Escudero, José Manuel; Ederra Urzainqui, Íñigo; Renaud, Cyril C.; Institute of Smart Cities - ISCIn this work, we propose the monolithic integration of Schottky barrier diodes (SBDs) and uni-traveling-carrier photodiodes (UTC-PDs) to implement optoelectronic terahertz heterodyne receivers. By performing efficient frequency-mixing with SBDs and generating the local oscillator (LO) signal by optical means in UTC-PDs the virtues of both electronic and photonic domains are incorporated into the same receiver. A complete modelling process including semiconductor, electromagnetic, and non-linear harmonic domains is used to design a subharmonic mixer (SHM) at 220-330 GHz using antiparallel SBDs within the UTC-PD epitaxial structure. This is done in co-planar waveguide (CPW) on a silicon oxynitride film and semi-insulating indium phosphide substrate. Simulations show remarkable performance featuring a dual-side-band (DSB) conversion loss as low as 8.2 dB, a noise temperature of 2500 K, and an intermediate-frequency (IF) 3dB-bandwidth of 25 GHz, which is achieved with a driving photocurrent of 5-15 mA.Publication Open Access Small-signal stability analysis of power converters with optimal pulsewidth modulation strategies(IEEE, 2023-08-31) Rosado Galparsoro, Leyre; Samanes Pascual, Javier; López Taberna, Jesús; Gubía Villabona, Eugenio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaOptimal pulsewidth modulation strategies are commonly used in power electronics applications with closed-loop controllers. However, there is a lack of specific studies in the literature that analyze and study the dynamics of these modulators, which makes it difficult to derive small-signal models for stability analysis and controller design. Moreover, in many studies, the influence of optimal pulsewidth modulation on the small-signal stability analysis is disregarded. This article addresses these issues by proposing a modeling methodology for optimal pulsewidth modulators, applied to a selective harmonic elimination modulator. The proposed methodology is based on the frequency response analysis, which is particularly convenient for controller design. The study shows that the classical zero-order hold model employed for carrier-based pulsewidth modulators is valid for characterizing the dynamics of optimal pulse-width modulation strategies. Simulation results validate this conclusion.Publication Open Access Diffusion models for remote sensing imagery semantic segmentation(IEEE, 2023-10-20) Ayala Lauroba, Christian; Sesma Redín, Rubén; Aranda, Carlos; Galar Idoate, Mikel; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA25-2022Denoising Diffusion Probabilistic Models have exhibited impressive performance for generative modelling of images. This paper aims to explore the potential of diffusion models for semantic segmentation tasks in the context of remote sensing. The major challenge of employing these models for semantic segmentation tasks is the generative nature of the model, which produces an arbitrary segmentation mask from a random noise input. Therefore, the diffusion process needs to be constrained to produce a segmentation mask that matches the target image. To address this issue, the denoising process is conditioned by utilizing the input image as a reference. In the experimental study, the proposed model is compared against other state-of-the-art semantic segmentation architectures using the Massachusetts Buildings Aerial dataset. The results of this study provide valuable insights into the potential of diffusion models for semantic segmentation tasks in the field of remote sensing.Publication Open Access Polymer-functionalized fiber-optic optrode towards the monitoring of breathing parameters(Institute of Electrical and Electronics Engineers Inc., 2023) Álvarez-Jiménez, A.; Acha Morrás, Nerea de; Aginaga Etxamendi, Concepción Isabel; Urrutia Azcona, Aitor; Socorro Leránoz, Abián Bentor; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCAn innovative application of lossy mode resonances (LMRs) is presented in this work, pursuing the detection of biomedical variables. In this case, the detection of pH and breathing signal events is shown by means of a reflective fiber-optic optrode consisting of a poly(allylamine chloride) / poly (acrylic acid) polymer matrix deposited on the tip of a 200-micron-core bare multimode optical fiber. The proposed sensor is capable of detecting pH values between 6.5 and 8.0 (saliva pH range) with quite stability and repeatability. Moreover, when monitoring the breathing signal, the proposed sensor presents quite good real time detection of the different events occurring during the inspiration-expiration cycle, different breathing rates and detecting apneas.