Author: Wilfrido Calleja Arriaga

Acquisition of corneal electrical signals by a simple method

DANIEL ROBLES CAMARILLO WILFRIDO CALLEJA ARRIAGA JOSE MARTIN HERRERA RAMIREZ (2010)

Conventional systems for electroretinography (ERG) use complex electronic circuit to get electrical corneal signals (ECS), they usually use dedicated data acquisition hardware to acquire the signal over the cornea’s eye. In this paper we proposed a simple method to acquire the ECS using the computer sound card to put into the PC the ECS. We show the results of the signals acquired from the cornea through microphone’s port.

Article

Retina Cornea Map of vision Electric stimulator CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA

Effects of wavelets transcorneal-stimulation on low vision patients with central retinal artery occlusion CRAO

DANIEL ROBLES CAMARILLO WILFRIDO CALLEJA ARRIAGA HUGO QUIROZ MERCADO (2010)

The present work presents the effect of wavelets waveforms electrical stimulation applied on lowvision (LV) patients suffering central retinal artery occlusion CRAO.Stimulations is done via transcorneal electrical stimulation (TES) by means of an adaptive wavelets system generator. The applied waveform signal is generated into a digital processor, and is based on a healthy eye’s multi‐focal wavelet signal obtained from electroretinography (MF‐ERG) response of healthy people. The stimulation protocol proposed in this paper is qualitatively different from others, like Inomata et. al. [1,2] that uses square bipolar signals. All stimulated patients improve at least one line in Fainbloom’s visual acuity exams scale. Results are correlated with an important increased in the electrical A and B wave response in standard electroretinography and with subjective patient’svisual acuity confirmed by the fact allstimulated patients improve at least one line in Fainbloom’s scale at least, in visual acuity exams.

Article

Eye Wavelet Patient Time stimulation CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA

Two-dimensional optical micro-scanner on silicon technology

GABRIELA MOLAR VELAZQUEZ FRANCISCO JAVIER RENERO CARRILLO WILFRIDO CALLEJA ARRIAGA (2010)

A two-dimensional optical micro-scanner, which main components are two mobile flat and a concave micro-mirrors, is designed such that, all optical components can be fabricated on the same substratum. The optical parameters, which physical dimensions are between 50 and 500 μm, are obtained within the geometrical optics. The optical performance is evaluated by means of the MTF and Rayleigh resolution criteria, given 80% of modulation for a frequency of 8 cycles/mm with a Gaussian source, the resolution limit is 30 μm.

Article

Optical design Micro-mirrors Micro-optical systems Integrated optics Oslo CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA

Degradation and Breakdown of W–La2O3 Stack after Annealing in N2

JOEL MOLINA REYES ALFONSO TORRES JACOME WILFRIDO CALLEJA ARRIAGA (2008)

We report the effect of relatively high-voltage stressing (under substrate injection) on the stress-induced leakage current (SILC) and breakdown of W–La2O3 stacked structures. It is shown that the gate area of the metal–insulator–semiconductor (MIS) devices under evaluation influences their final degradation characteristics after stress. Once the samples reach breakdown, their post-breakdown current–voltage (I–V) characteristics suggest that leakage spots are highly localized and are caused by the accumulation of defects.

Article

PMA SILC Breakdown Reliability CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA

Design and simulation of an integrated wireless capacitive sensors array for measuring ventricular pressure

NATIELY HERNANDEZ SEBASTIAN Daniela Diaz_Alonso Francisco-J Renero-C Noé Villa_Villaseñor WILFRIDO CALLEJA ARRIAGA (2018)

This paper reports the novel design of a touch mode capacitive pressure sensor (TMCPS) system with a wireless approach for a full-range continuous monitoring of ventricular pressure. The system consists of two modules: an implantable set and an external reading device. The implantable set, restricted to a 2 2 cm2 area, consists of a TMCPS array connected with a dual-layer coil, for making a reliable resonant circuit for communication with the external device. The capacitive array is modelled considering the small deflection regime for achieving a dynamic and full 5–300 mmHg pressure range. In this design, the two inductive-coupled modules are calculated considering proper electromagnetic alignment, based on two planar coils and considering the following: 13.56 MHz frequency to avoid tissue damage and three types of biological tissue as core (skin, fat and muscle). The system was validated with the Comsol Multiphysics and CoventorWare softwares; showing a 90% power transmission efficiency at a 3.5 cm distance between coils. The implantable module includes aluminum- and polyimide-based devices, which allows ergonomic, robust, reproducible, and technologically feasible integrated sensors. In addition, the module shows a simplified and low cost design approach based on PolyMEMS INAOE® technology, featured by low-temperature processing.

Author Contributions: N.H.-S.: Conceptualization, Formal analysis, Investigation, Methodology, Software, Visualization andWriting original draft. D.D.-A.: Formal analysis, Investigation, Methodology and Validation. F.J.R.-C.: Investigation, Resources and Validation; N.V.-V.: Software, Resources and Validation. W.C. A.: Project administration, Resource, Supervision, Visualization, Writing-review and editing.

Acknowledgments: Natiely Hernandez Sebastián acknowledges Conacyt program scholarship #549792

Article

RF MEMS Pressure sensor MEMS resonators Implantable BioMEMS Flexible electronics Touch mode capacitive sensor INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ORDENADORES DISEÑO DE SISTEMAS SENSORES DISEÑO DE SISTEMAS SENSORES

Design and simulation of an integrated wireless capacitive sensors array for measuring ventricular pressure

NATIELY HERNANDEZ SEBASTIAN Daniela Diaz_Alonso Francisco-J Renero-C Noé Villa_Villaseñor WILFRIDO CALLEJA ARRIAGA (2018)

This paper reports the novel design of a touch mode capacitive pressure sensor (TMCPS) system with a wireless approach for a full-range continuous monitoring of ventricular pressure. The system consists of two modules: an implantable set and an external reading device. The implantable set, restricted to a 2 2 cm2 area, consists of a TMCPS array connected with a dual-layer coil, for making a reliable resonant circuit for communication with the external device. The capacitive array is modelled considering the small deflection regime for achieving a dynamic and full 5–300 mmHg pressure range. In this design, the two inductive-coupled modules are calculated considering proper electromagnetic alignment, based on two planar coils and considering the following: 13.56 MHz frequency to avoid tissue damage and three types of biological tissue as core (skin, fat and muscle). The system was validated with the Comsol Multiphysics and CoventorWare softwares; showing a 90% power transmission efficiency at a 3.5 cm distance between coils. The implantable module includes aluminum- and polyimide-based devices, which allows ergonomic, robust, reproducible, and technologically feasible integrated sensors. In addition, the module shows a simplified and low cost design approach based on PolyMEMS INAOE® technology, featured by low-temperature processing.

Author Contributions: N.H.-S.: Conceptualization, Formal analysis, Investigation, Methodology, Software, Visualization andWriting original draft. D.D.-A.: Formal analysis, Investigation, Methodology and Validation. F.J.R.-C.: Investigation, Resources and Validation; N.V.-V.: Software, Resources and Validation. W.C. A.: Project administration, Resource, Supervision, Visualization, Writing-review and editing.

Acknowledgments: Natiely Hernandez Sebastián acknowledges Conacyt program scholarship #549792

Article

RF MEMS Pressure sensor MEMS resonators Implantable BioMEMS Flexible electronics Touch mode capacitive sensor INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ORDENADORES DISEÑO DE SISTEMAS SENSORES DISEÑO DE SISTEMAS SENSORES

Design of a fully integrated inductive coupling system: a discrete approach towards sensing ventricular pressure

Natiely Hernández Sebastián Noé Villa_Villaseñor Francisco-J Renero-C Daniela Diaz_Alonso Wilfrido Calleja Arriaga (2020)

In this paper, an alternative strategy for the design of a bidirectional inductive power transfer (IPT) module, intended for the continuous monitoring of cardiac pressure, is presented. This new integrated implantable medical device (IMD) was designed including a precise ventricular pressure sensor, where the available implanting room is restricted to a 1.8 × 1.8 cm2 area. This work considers a robust magnetic coupling between an external reading coil and the implantable module: a three-dimensional inductor and a touch mode capacitive pressure sensor (TMCPS) set. In this approach, the coupling modules were modelled as RCL circuits tuned at a 13.56 MHz frequency. The analytical design was validated by means of Comsol Multiphysics, CoventorWare, and ANSYS HFSS software tools. A power transmission efficiency (PTE) of 94% was achieved through a 3.5 cm-thick biological tissue, based on high magnitudes for the inductance (L) and quality factor (Q) components. A specific absorption rate (SAR) of less than 1.6 W/Kg was attained, which suggests that this IPT system can be implemented in a safe way, according to IEEE C95.1 safety guidelines. The set of inductor and capacitor integrated arrays were designed over a very thin polyimide film, where the 3D coil was 18 mm in diameter and approximately 50% reduced in size, considering any conventional counterpart. Finally, this new approach for the IMD was under development using low-cost thin film manufacturing technologies for flexible electronics. Meanwhile, as an alternative test, this novel system was fabricated using a discrete printed circuit board (PCB) approach, where preliminary electromagnetic characterization demonstrates the viability of this bidirectional IPT design.

Article

Integrated coupling system Ventricular pressure sensor BioMEMS Flexible electronics Wireless power transfer Implantable medical device INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ORDENADORES DISEÑO DE SISTEMAS SENSORES DISEÑO DE SISTEMAS SENSORES

Electrical characterization of a-C:H as a dielectric material in metal/insulator/metal structures

CARLOS ZUÑIGA ISLAS ANDREY KOSAREV ALFONSO TORRES JACOME PEDRO ROSALES QUINTERO WILFRIDO CALLEJA ARRIAGA FRANCISCO JAVIER DE LA HIDALGA WADE OLEKSANDR MALIK (2010)

The fabrication and electrical characterization of Metal- Insulator-Metal (MIM) structures, using a-C:H films as the insulating material, are presented in this work. These PECVD carbon films show a very low dielectric constant and a very high resistivity. The current conduction mechanisms were analyzed before and after the post deposition annealing in pure argon ambient at 400°C. For as-deposited films, the experimental J-U curves showed that under low biasing regime (|U| < 8 V) the space charge limited current conduction is the main transport mechanism, whereas under higher biasing regime (|U| > 8 V)) the current transport is dominated by the Schottky mechanism. For annealed structures, under low and high biasing the ohmic and Schottky mechanisms were identified as the main processes for the electrical transport. Finally, we found that both parameters, the dielectric constant and resistivity, decrease slightly after the thermal annealing.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA

Resonador sensor de masa: desarrollo y métodos de medición

SALVADOR ALCANTARA INIESTA BLANCA SUSANA SOTO CRUZ Wilfrido Calleja Arriaga GABRIEL ROMERO PAREDES RUBIO MARGARITA GALINDO MENTLE (2010)

The cantilevers are one of the most simple mechanical resonator structure used to detect a mass variations from its resonance frequency. In microelectronic field, is possible to fabricate this kind of detector with the whole electronic circuit on the same substrate, extending the applications even in biological and chemical environment. The performance of these sensors depends of its dimensions, material, excitation electronic stage, and displacement amplitude. In this work, we present the fabrication process to obtain a sensor with dimensions of 100X20X15μm from silicon semiconductor technology and bulk micromachining techniques. Also, we describe the characterization method through a Matlab data acquisition system and IR sensors, in order to obtain the frequency resonance and amplitude of these cantilevers with resolutions of Hz and μm respectively. The results obtained show that the methods proposed are useful to detect mass variations from deposited films or adsorbed materials on these silicon cantilevers in orders to μg.

Un resonador mecánico tipo trampolín es una estructura sencilla con la que se logra la detección de masa a partir de cambios de frecuencia de resonancia. Es posible fabricar este tipo de detector con técnicas de microelectrónica, lo cual lo convierte en un potencial sensor para ser integrado con el circuito de acondicionamiento y ser usado en aplicaciones químicas o biológicas. El desempeño de estos sensores dependerá de sus dimensiones, del tipo de material, de la eficacia de excitación y de la exacta transducción de la amplitud de desplazamiento del resonador. En este trabajo se presenta el proceso para la obtención de trampolines de silicio de 100x20x15μm, fabricados con tecnología planar y técnicas de micromaquinado en espesor. Se describe el método de caracterización de trampolines en frecuencia y amplitud mediante un programa y adquisición de datos en PC y un sensor de IR reflectivo, con resolución del orden de Hz y μm. Ambos métodos pueden ser útiles en las mediciones de los trampolines de silicio para la detección de masa de materiales depositados o adsorbidos en la superficie con resolución de μg.

Article

Resonator Cantelever Resonance Sensor Mass Microelectronic Bulk micromachining Resonador Trampolín Resonancia Sensor Masa Microelectrónica Micromaquinado en espesor CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA

Óxido de silicio SOG como dieléctrico de compuerta recocido a 200°C

MIGUEL ANGEL DOMINGUEZ JIMENEZ Pedro Rosales Quintero ALFONSO TORRES JACOME Joel Molina Reyes MARIO MORENO MORENO CARLOS ZUÑIGA ISLAS Wilfrido Calleja Arriaga (2011)

En este trabajo, se ha realizado la caracterización del oxido de silicio SOG (SOG-SiO2) depositado por la técnica sol-gel y recocido a 200 °C. Los resultados de la caracterización óptica y eléctrica muestran que los valores del índice de refracción (n) y de la constante dieléctrica (k) son muy cercanos a aquellos valores comúnmente reportados para el SiO2 crecido térmicamente. Nuestros resultados sugieren que el SOG-SiO2 recocido a 200 °C puede ser una alternativa para mejorar las características eléctricas de los transistores de película delgada (TFTs), entre otros dispositivos que son fabricados a bajas temperaturas.

Currently, the flexible electronics research field is of high interest because of the development of low cost products, such as solar cells and LCDs. Low temperature deposition processes are required in order to use flexible substrates. Nevertheless, the performance of the electronic devices built at temperatures below 350 °C is not as good as in CMOS technology. Thus, physical and electrical properties of semiconductor and insulator materials deposited at these low temperatures must be improved. In this work, characterization of SiO2 annealed at 200°C has been done. The optical and electrical characterization showed that the refractive index (n) and dielectric constant (k) values are similar to those of thermally grown SiO2. As can be observed, these results suggest that this SiO2 annealing at 200°C could be an alternative to improve electrical characteristics of TFTs, among other device applications.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA