This article presents the design and implementation of a micropositioning system actuated by three piezoelectric stacks to control its displacements on XYZ axes. The use of conventional piezoelectric buzzers allows us to reduce fabrication costs. The working or mobile platform is the base for objects that will be manipulated, for example, in automated assembling. The micropositioner can be integrated into a microgripper to generate a complete manipulation system. For micropositioner fabrication, at first, Polylactic Acid (PLA) was chosen as the structural material, but after simulation and some experimental tests performed with a micropositioner made of Acrylonitrile Butadiene Styrene (ABS), it showed larger displacement (approx. 20%) due to its lower stiffness. A third test was performed with a positioner made with Polyethylene Terephthalate Glycol (PETG), obtaining an intermediate performance. The originality of this work resides in the geometrical arrangement based on thermoplastic polymer compliance mechanisms, as well as in the use of additive manufacturing to fabricate it. An experimental setup was developed to carry out experimental tests. ANSYS™ was used for simulation.

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 effect of the galvanic corrosion process taking place between aluminium alloy (AA2024-T3) and carbon fiber reinforced plastic (CFRP) immersed in 0.05 M NaCl was studied using organic and inorganic compounds as corrosion inhibitors. Electrochemical approaches such as electrochemical noise analysis (ENA) and electrochemical impedance spectroscopy (EIS) were carried out to evaluate efficiencies of 1,2,4-triazole (C₂H₃N₃) and cerium nitrate hexahydrate (Ce(NO₃)₃·6H₂O) as corrosion inhibitors. The highest efficiency was reached for Ce(NO₃)3.6H₂O, with some improvement observed by adding C₂H₃N₃ in a mixed inhibitor solution. The noise resistance (R_n) and polarization resistance (R_p) values calculated from ENA and EIS data showed almost identical behavior with different magni­tudes but similar trends. Adsorption isotherm models estimated with fractional surface coverage (q) parameter were fitted better to Langmuir model for C₂H₃N₃ and Temkin model for Ce(NO₃)₃·6H₂O. The calculated values of Gibbs free energy suggested physi­sorption and chemisorption as spontaneous interactions between a metal surface and both inhibitors. Energy-dispersive X-ray spectroscopy (EDS) was carried out before and after immersing AA2024-T3 in the electrolyte, identifying rich zones in copper with cerium deposited over it and confirming the presence of rare-earth oxide deposition and oxide film products. The EDS analysis for CFRP revealed the deposition of Ce and Al particles over its surface after immersion in the electrolyte, especially in the areas rich in carbon.

La comunicación inalámbrica, mejor conocida como Wi-Fi (Wireless Fidelity), adquiere interés ya que no requiere del uso de cables, los cuales son engorrosos y limitan el espacio libre. Este tipo de comunicación es ampliamente utilizado en equipos electrónicos, principalmente en el hogar y la industria. Las antenas de parche, que usan algunos de estos equipos, son muy populares debido a sus características. El objetivo de este trabajo es obtener un prototipo de antena de parche eficiente y económico para su uso en interiores y exteriores. En principio, se presenta el prototipo de una antena de parche rectangular diseñada para Wi-Fi con polarización lineal. Después, se realizan sobre ella cortes y ranuras, para mejorar su ganancia. Las pruebas realizadas con la antena individual con cuatro cortes muestra la factibilidad de su uso para interiores. Posteriormente, se diseña un arreglo de antenas de parche en base a la antena individual de cuatro cortes, con la finalidad de obtener un prototipo mejorado. Las pruebas demuestran un buen desempeño del arreglo de antenas propuesto, para su uso en interiores y exteriores, como se esperaba.

A Novel Displacement-amplifying Compliant Mechanism Implemented on a Modified Capacitive Accelerometer

The feasibility study is crucial for decision-making in the investment stage of photovoltaic systems projects. A cost–benefit analysis for a project should not be evaluated solely in terms of money in-flows and outflows; it is important to consider other characteristics such as climate, solar irradiation, and the hours of sunshine in different spaces, as well as the electricity rates of the electricity supply company. Therefore, analyzing and simulating the performance conditions, both technical and economic, of photovoltaic systems is key. The objective of this study was to analyze the investment models in two types of photovoltaic systems: one integrated into the construction and the other conventional in a building in the Mexican Republic, considering ideal conditions, thus evaluating the energy efficiency in cities, as they consume around two-thirds of the world’s energy and are responsible for 70% of global greenhouse gas emissions. The methodological proposal was to select a location, determine the predominant type of climate and collect data on solar radiation, the electricity supplier rates, the profitability for a cost–benefit analysis, and the inflation rates to determine the viability of a project that comprehensively covers the variables for decision-making.