José Mireles Jr. Garcia

El monitoreo y diagnóstico de transformadores de potencia es fundamental para garantizar la confiabilidad de los sistemas eléctricos. Se han desarrollado tecnologías que emplean sensores y dispositivos ópticos como solución para aplicaciones de potencia. En este trabajo se presenta un estudio del comportamiento electromagnético del encapsulado de un acelerómetro basado en un sistema micro-opto-electro-mecánico (MOEMS), bajo la influencia de un campo magnético externo generado por un transformador. El desempeño se evaluó mediante simulaciones bidimensionales en ANSYS Maxwell, comparando dos materiales: cobre (Cu) y alúmina (Al₂O₃). El modelo incluyó la simulación de un transformador con una bobina de 80 espiras, corriente de 20 A y frecuencia de 60 Hz. En el encapsulado de cobre, la exposición al campo magnético del transformador generó una densidad de corriente de Eddy de 15.76 A/m² y un campo magnético secundario de 0.2 μT. Con estos parámetros, se cuantificaron la potencia disipada por efecto Joule, la fuerza de Lorentz y la aceleración asociada, obteniéndose valores considerablemente bajos. En contraste, el encapsulado de alúmina no presentó corrientes inducidas ni campos secundarios, lo que indica una interacción electromagnética no apreciable.

Micro-electro-mechanical systems (MEMS) sensors offer the benefits of compact size, lightweight design, and low cost, which has led to widespread use in consumer electronics, vehicles, healthcare, defense, and communications. As their performance has improved, MEMS sensors have also found applications in oil exploration and geophysical studies. Pressure and temperature measurements during hydraulic fracturing have long been employed to improve downhole conductivity during oil and gas extraction. Nevertheless, the development of high-precision MEMS sensors for oil exploration remains an active area of research. This paper presents the design, fabrication, packaging, and characterization of a silicon-on-insulator (SOI) MEMS piezoresistive pressure sensor integrated with a temperature sensor. It also describes the design of a chamber intended to emulate conditions at the bottom of oil exploration wells. The sensors were successfully designed and fabricated on the basis of physics-based simulations, deep reactive ion etching and anodic bonding. The pressure sensors, together with the signal-conditioning system, exhibited a linear response with a sensitivity of 0.0268 mV/V/MPa and maximum hysteresis of 5.3%.

Micro-electro-mechanical systems (MEMS) sensors offer the benefits of compact size, lightweight design, and low cost, making them widely applicable in consumer electronics, vehicles, health, defense, and communications. With enhanced performance, MEMS sensors have also found applications in oil exploration and geophysical studies. For years, pressure and temperature sensing during hydraulic fracturing has been employed to enhance the down-hole conductivity of oil and gas extraction. Nevertheless, the pursuit of developing high-precision MEMS sensors for oil exploration continues to be an active area of research. This paper details the design, fabrication, packaging, and characterization of a silicon-on-insulator (SOI) MEMS piezoresistive pressure sensor integrated with a temperature sensor. It also describes the design of a chamber that simulates real conditions at the bottom of oil exploration wells. The sensors were successfully designed and fabricated based on physics-based simulations, deep reactive ion etching and anodic bonding techniques. The pressure sensors, along with the signal conditioning system, demonstrated a linear response, with a maximum linear error of 4.95% at 7 MPa and a reduced linear error of less than 3.5% at 24 MPa. Additionally, a quadratic approximation for the temperature sensors was achieved, showing a maximum resistance change of 8.5% at 140 ºC.

The digital transformation based on artificial intelligence supports the development of communities, organizations and nations that are economically committed to the technology that enables it, however, there are many spaces that remain empty if only a non-inclusive digital transformation is committed, so This study aims to explain the relationship between solidarity technologies and digital solidarity to promote digital transformation based on artificial intelligence, based on the theory of justice, solidarity and innovation. The research is quantitative, non-experimental, transectional, explanatory, case study of the Artificial Intelligence Center – IA.Center State of Chihuahua where 180 questionnaires were applied, analyzed by partial least squares structural equation modeling (PLS-SEM), using the SmartPLS software 4. The findings reveal that solidarity technology positively and significantly impacts digital solidarity and that digital solidarity positively and significantly impacts AI digital transformation. Another finding is that digital solidarity is a mediating variable between the positive and significant relationship between solidarity technology and AI digital transformation. It was also found that the predictive power of the global model is significant. It is concluded that just as paid technology favors digital transformation, so do solidarity technologies and digital solidarity.

The objective of this study is to analyze the weaknesses and actors of technological entrepreneurship in Latin America, as well as to describe a case study where its actors work to reduce these weaknesses. The methodology with a qualitative approach based on the theory of resources and capabilities is divided into two stages: the first is a documentary analysis of three international entrepreneurship reports: Global Entrepreneurship Monitor, Dynamic Entrepreneurship Index and Global Startup Ecosystem Index, identifying weaknesses and actors through content analysis; in the second, a case study organization is described at the meso level, focused on technological entrepreneurship and artificial intelligence called: Artificial Intelligence Center - IA.Center State of Chihuahua. The results present the weaknesses of the countries evaluated with the highest entrepreneurship in LA: human capital and entrepreneurial education, CTI platform, business structure, government policy, access to financing and R&D transfers; as well as the role played by its stakeholders in education, government, finance, and innovation and technology. Finally, it described the mission, business model and actions carried out by the case study to reduce the weaknesses of regional technological entrepreneurship.

En esta obra se presenta una introducción a los Circuitos Integrados, enfocándose posteriormente en los fundamentos del análisis de algunos dispositivos MEMS representativos, abordando con detalle la metodología de diseño de la viga en voladizo, el actuador chevrón y el acelerómetro, así como de un resonador y un microgenerador piezoeléctrico. Se presentan también los principios básicos de fabricación y se muestra el potencial de uso del grafeno. Además, se presentan los principios básicos y ejemplos de la simulación por elemento finito en Ansys, ya que, tanto el modelado teórico, como numérico y la fabricación constituyen temas indispensables para quienes tengan el interés de iniciar o consolidar su conocimiento en este interesante e innovador tema. Introducción a los circuitos integrados, enfocándose posteriormente en los fundamentos del análisis de algunos dispositivos MEMS representativos, abordando con detalle la metodología de diseño de la viga en voladizo, el actuador chevrón y el acelerómetro, así como de un resonador y un microgenerador piezoeléctrico. Se presentan también los principios básicos de fabricación y se muestra el potencial de uso del grafeno. Además, se presentan los principios básicos y ejemplos de la simulación por elemento finito en Ansys®, ya que, tanto el modelado teórico, como numérico y la fabricación constituyen temas indispensables para quienes tengan el interés de iniciar o consolidar su conocimiento en este interesante e innovador tema.

Homodyne demodulation is a convenient technique for signal detection in interferometric sensors. The demodulation process is typically developed using analog circuits. However, to improve the performance of the demodulator, a digital system must be employed. In this study, we developed an optical fiber sensor by combining: (a) a Michelson interferometer, (b) a micro-electro-mechanical system (MEMS) device, and (c) a field-programmable gate array (FPGA)-based interrogator. Signal processing was integrated into the FPGA-embedded system. The homodyne demodulation algorithm was implemented with hardware modules developed in the hardware description language (HDL) to provide a portable, low-cost, and scalable digital system. The present study successfully demonstrates the development and validation of an FPGA-based interrogator capable of processing interferograms through a homodyne demodulation scheme. The experimental results reveal proper displacement measurements of the proof-mass MEMS and the low amount of hardware resources used. The displacement measurements obtained from the system matched those obtained from a certified characterization system. As the system can be easily reconfigured to the required measured signal, a similar measurement methodology can be developed using other demodulation schemes and optical fiber sensors.

The micro-electromechanical system (MEMS) sensors are suitable devices for vibrational analysis in complex systems. The Fabry–Pérot interferometer (FPI) is used due to its high sensitivity and immunity to electromagnetic interference (EMI). Here, we present the design, fabrication, and characterization of a silicon-on-insulator (SOI) MEMS device, which is embedded in a metallic package and connected to an optical fiber. This integrated micro-opto-electro-mechanical system (MOEMS) sensor contains a mass structure and handle layers coupled with four designed springs built on the device layer. An optical reading system using an FPI is used for displacement interrogation with a demodulation technique implemented in LabVIEW^®. The results indicate that our designed MOEMS sensor exhibits a main resonant frequency of 1274 Hz with damping ratio of 0.0173 under running conditions up to 7 g, in agreement with the analytical model. Our experimental findings show that our designed and fabricated MOEMS sensor has the potential for engineering application to monitor vibrations under high-electromagnetic environmental conditions.

Microgrippers are devices that have found applications in various fields of research and industry. They are driven by various actuation methods. In this article, an electrothermal rotary actuator recently proposed in the literature is explored to obtain a novel microgripper design (Model 1). In addition, the use of the rotary actuator as part of the chevron actuated microgrippers (Model 2) is also discussed. The theoretical analysis of the rotary actuator is supported by an equivalent U-shaped-like microactuator. The small error values validate the approximation used. Numerical modeling is performed with ANSYS^TM (Student version 2022, ANSYS, PA, USA). A comparison of theoretical and numerical results provides acceptable error values. The total inter-jaw displacement values obtained for models 1 and 2 are 12.28 μm and 21.2 μm, respectively, and the reaction force is 8.96 μN and 34.2 μN, respectively. The performance parameters of both microgrippers could make their use feasible for different nanoapplications. Model 2 can be used when higher force and displacement are required.

The design of a novel electrothermal microgripper device is shown, which is based on an improved chevron type actuator developed considering their elements parameterization, whose resistive model is also provided. The performance of the microgripper’s parameters, such as displacement, force, and temperature distribution, with convection for the voltage range from 0 up to 5 V, is evaluated through numerical and analytical simulation. Microgripper design was also improved with aid of parameterization. The effect on the microgripper performance due to its thickness is also analyzed, finding a considerable increment in force, when thickness increases. Its main advantage is given by the simplicity of the compliance arrangement of the microgrippers jaws. Considering convection, when 5 V are applied, 37.72 °C was generated at the jaw’s tips of the Improved Microgripper 2 (IMG2), implemented with silicon, this relatively low temperature increases its capabilities of application. When the IMG2 is implemented with polysilicon, its response is competitive comparing with a more complex microgripper, increase of displacement (50%) is shown, but a decrement of force (30%). The diameters allowed for the subjection objects are found between 84.64 µm and 108 µm, with weights lower than 612.2 µg. Some tests of subjection were performed using microcylinders of Au, glass ceramic, polycarbonate and carbon fiber, showing a permissible stress on them, considering its Young’s modulus, as well as the total reaction force induced. All simulations were done on Ansys software. The results demonstrate the feasibility of the future microgripper fabrication.