Open Access
Planar-waveguide-lmr-based sensors: engineering the depth of characteristic curves
(IEEE, 2023) Shrivastav, Anand M.; Del Villar, Ignacio; Ascorbe Muruzabal, Joaquín; Corres Sanz, Jesús María; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Lossy mode resonance (LMR)-based sensors have been proven as one of the exponentially growing research fields since the last decade. These sensors have demonstrated their capabilities in the detection of several physical, chemical, and biological entities, such as refractive index, humidity, gases, enzymes, etc. Conventionally, LMR-based sensors are developed using optical fiber as the sensing platform, but to increase the broad range of applications and better tenability, planar waveguide substrates for LMR realization have been introduced in the last few years. This provides a greater degree of freedom for the sensor design such as tunability in substrate thickness, material, and better surface immobilization. The current study focuses on evaluating the effect of substrate thickness on LMR-based optical sensors to achieve higher sensing performance. For experiments, 150-μm-thick glass coverslips are used as the thin planer substrate, which is then coated with a few nanometers thick LMR-supported SnO 2 layer using the dc sputtering method. Furthermore, to monitor the effect of the changing substrate thickness, the width of the glass coverslip is reduced through the chemical etching process using the 40% HF solution, and simultaneously, the changes in LMR spectra are analyzed. The study shows that the depth of LMR curves strongly depend on the thickness of the waveguide providing LMRs with lower substrate thickness possesses higher depth. Greater depth in LMR curves is a crucial factor in identifying the minimum transmission wavelength of resonance, making it easier to track and detect the targeted parameter. This characteristic greatly enhances the applicability of LMR-based sensors in industrial applications.
Open Access
Single-mode-multimode-single-mode and lossy mode resonance-based devices: a comparative study for sensing applications
(Springer-Verlag, 2015) Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Corres Sanz, Jesús María; Del Villar, Ignacio; Hernáez Sáenz de Zaitigui, Miguel; Socorro Leránoz, Abián Bentor; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC
Open Access
Tapered single-mode optical fiber pH sensor based on lossy mode resonances generated by a polymeric thin-film
(IEEE, 2012) Socorro Leránoz, Abián Bentor; Del Villar, Ignacio; Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Lossy mode resonances can be generated with certain polymeric nanostructures, such as those obtained with a multilayered assembly of poly(allylamine hydrochloride) and poly (acrylic acid). This coating is adsorbed by the electrostatic self assembly technique onto a tapered single-mode optical fiber, in order to evaluate its performance when detecting pH. According to the results reported in this work, the high sensitivity given by a tapering process in a single-mode optical fiber is increased by the effect of this kind of electromagnetic resonances. Particularly, in a pH range from 4.0 to 6.0 the overall wavelength shift of this sensor reaches 200 nm and the transmission at the resonance wavelengths can fall down to -50 dB. These data provide results which can be taken into account to detect pH with high accuracy.
Open Access
Methodology to assess the impact of the introduction of new technologies in smart cities
(Federación de Asociaciones de Ingenieros Industriales de España, 2015) Branchi, Pablo Emilio; Fernández Valdivielso, Carlos; Matías Maestro, Ignacio; Institute of Smart Cities - ISC
Estamos frente a una revolución producto de los sistemas digitales y de comunicación, donde el papel de la tecnología continuará creciendo exponencialmente. Está calando profundamente en la sociedad, y tiene un alto impacto en las infraestructuras, los sistemas de transporte, en los edificios y en el espacio público. En el ámbito urbano se reconfigura el escenario tradicional tecnológico, con sistemas que generan nuevas necesidades, descubriendo nuevas realidades que buscan nuevas soluciones. El objetivo de este trabajo es el de establecer una metodología para la elaboración de una herramienta de evaluación para las diferentes tecnologías en función de su utilidad y consecuencias, contemplando la incidencia de sus aplicaciones. Con ella se podrán evaluar, por parte de políticos y técnicos prescriptores, las ventajas y desventajas de cada iniciativa, las virtudes de las tecnologías y sistemas disponibles, y el modo óptimo de su aplicación en las Ciudades Inteligentes.
Open Access
SnO2 based optical fiber refractometers
(SPIE, 2012) Sánchez Zábal, Pedro; Ruiz Zamarreño, Carlos; Hernáez Sáenz de Zaitigui, Miguel; Del Villar, Ignacio; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
In this work, the fabrication and characterization of refractometers based on lossy mode resonances (LMR) is presented. Tin dioxide (SnO2) films deposited on optical fibers are used as the LMR supporting coatings. These resonances shift to the red as a function of the external refractive index, enabling the fabrication of robust and highly reproducible wavelength-based optical fiber refractometers. The obtained SnO2-based refractometer shows an average sensitivity of 7198 nm/refractive index unit (RIU) in the range 1.333-1.420 RIU.
Open Access
Ultrahigh sensitive detection of tau protein as Alzheimer's biomarker via microfluidics and nanofunctionalized optical fiber sensors
(Wiley, 2022) Chiavaioli, Francesco; Santano Rivero, Desiree; Del Villar, Ignacio; Socorro Leránoz, Abián Bentor; Zhang, Xuejun; Li, Kaiwei; Santamaría Martínez, Enrique; Fernández Irigoyen, Joaquín; Baldini, Francesco; Van den Hove, Daniel L. A.; Shi, Lei; Bi, Wei; Guo, Tuan; Giannetti, Ambra; Matías Maestro, Ignacio; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Alzheimer’s disease (AD) is one of the most common neurodegenerative illnesses displaying the highest death rate in the elderly. However, the existing AD diagnostic system remains elusive due to lack of a technology that may ensure enough sensitivity and reproducibility, detection accuracy, and specificity. Herein, a straightforward approach is reported to realize lab-on-fiber (LoF) technology for AD biomarker detection based on a D-shaped single-mode fiber combined with nanometer-scale metal-oxide film. The proposed sensing system, which permits the generation of lossy-mode resonance (LMR), remarkably increases the evanescent field of light guided through the fiber, and hence the fiber-surrounding medium interaction. Moreover, such optical sensors are highly repeatable in results and can safely be embedded into a compact and stable microfluidic system. Herein, the specific detection of Tau protein (as one of the classical AD biomarkers that is highly correlated with AD progression) in a complex biofluid with a detection limit of 10 12 M and over a wide concentration range (10 3 –10 μg mL 1 ) is successfully demonstrated. The proposed LoF biosensor is an appealing solution for rapid, sub-microliter dose and highly sensitive detection of analytes at low concentrations, hereby having the potential toward early screening and personalized medicine in AD.
Open Access
Monitoring of water freeze-thaw cycle by means of an etched single-mode - multimode - single-mode fiber-optic refractometer
(IEEE, 2023) Socorro Leránoz, Abián Bentor; Aginaga Etxamendi, Concepción Isabel; Díaz Lucas, Silvia; Urrutia Azcona, Aitor; Del Villar, Ignacio; Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
As an alternative to the different technologies that permit the detection of in-situ ice formation on different surfaces, this contribution proposes the design of an etched single-mode – multimode – single-mode (E-SMS) fiber-optic-based structure as a multimode interference refractometer. This sensor provides enhanced properties with respect to a basic SMS structure, including a higher sensitivity and periodical interferometry bands that can measure surrounding refractive indices with repeatability and robustness. Since ice and water refractive indices are sufficiently different, this structure has been used to detect the freezing - thawing process of water taking place inside a freezer between -20°C and +20°C. Also, this work intends to show a proof of concept of a simple technology that can be applied in different situations, such as in smart cities, avionics, structural health monitoring or even to avoid a cold chain breakage. Inside, novel developments to better understand the working operation of the E-SMS structure are shown, together with a study on how to correlate optical and thermal measurements from a refractive index point of view.
Embargo
Experimental study of sensing performance using hyperbolic mode resonances
(Elsevier, 2025-01-01) Matías Maestro, Ignacio; Del Villar, Ignacio; Corres Sanz, Jesús María; González Salgueiro, Lázaro José; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Surface plasmon resonance (SPR) and lossy mode resonance (LMR) are prominent sensing mechanisms utilized across various fields. The Kretschmann configuration is commonly employed for SPR, while LMR is favored in planar waveguides or optical fibers due to high incidence angles. Recently, hyperbolic mode resonance (HMR) has emerged as a hybrid approach, combining metallic and dielectric thin films. This study explores the impact of incidence angle on HMR using the Kretschmann configuration. Four samples with varying gold (Au) and tin dioxide (SnO2) layer thicknesses were fabricated and characterized using Atomic Force Microscopy (AFM). Experimental setups employed the Kretschmann configuration for reflectance spectrum analysis. Results indicate enhanced sensitivity and figure of merit (FoM) with an additional SnO2 layer compared to the case without SnO2. Particularly with a 36 nm Au thickness the sensitivity doubles and the FoM improves by 16 %. Numerical simulations validate these findings, confirming the optimized performance of HMR for specific layer thicknesses and incidence angles.
Open Access
Fiber-optic biosensor based on lossy mode resonances
(Elsevier, 2012) Socorro Leránoz, Abián Bentor; Corres Sanz, Jesús María; Del Villar, Ignacio; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Open Access
Lossy mode resonance based microfluidic platform developed on planar waveguide for biosensing applications
(MDPI, 2022) Benítez Pérez, Melanys; Zubiate Orzanco, Pablo; Del Villar, Ignacio; Socorro Leránoz, Abián Bentor; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The development of resonance phenomena-based optical biosensors has gained relevance in recent years due to the excellent optical fiber properties and progress in the research on materials and techniques that allow resonance generation. However, for lossy mode resonance (LMR)-based sensors, the optical fiber presents disadvantages, such as the need for splicing the sensor head and the complex polarization control. To avoid these issues, planar waveguides such as coverslips are easier to handle, cost-effective, and more robust structures. In this work, a microfluidic LMR-based planar waveguide platform was proposed, and its use for biosensing applications was evaluated by detecting anti-immunoglobulin G (anti-IgG). In order to generate the wavelength resonance, the sensor surface was coated with a titanium dioxide (TiO2) thin-film. IgG antibodies were immobilized by covalent binding, and the detection assay was carried out by injecting anti-IgG in PBS buffer solutions from 5 to 20 μg/mL. The LMR wavelength shifted to higher values when increasing the analyte concentration, which means that the proposed system was able to detect the IgG/anti-IgG binding. The calibration curve was built from the experimental data obtained in three repetitions of the assay. In this way, a prototype of an LMR-based biosensing microfluidic platform developed on planar substrates was obtained for the first time