Size Of Electronic Systems Research Articles

Numerical analysis of forced convective heat transfer of nanofluids in microchannel for cooling electronic equipment

Abstract Electronic components depend on the passage of electric current to perform their duties, and they become potential sites for excessive heating, since the current flow through a resistance is accompanied by heat generation. The heat generated must be removed by designing a suitable thermal management system for reliable operation of the electronic device. Also the size of electronic systems used in industries such as microelectronics, telecommunications, aerospace, biomedical, robotics and similar other areas are rapidly decreasing. Unless properly designed and controlled, high rates of heat generation result in high operating temperatures for electronic equipment, which jeopardizes its safety and reliability. With the advent of micro-manufacturing technology, multiple micro channels are machined on the back of the substrates of electronic components in integrated circuits. The heat generated by the electronic component is transferred to the coolant by forced convection. In the present study analysis on a rectangular microchannel heat sink was done by using water, Al2O3-water, and TiO2-water nanofluids as working fluids. The nanofluid properties were evaluated with correlations available in the literature. The hydrodynamic and thermal behavior of a microchannel was studied in the present work. The variation wall temperature, pressure drop in the channel and the heat transfer rate was calculated. The effect of Reynolds number on heat transfer in the microchannel was also studied. A significant improvement in the heat transfer was found with microchannel heat sink due to decrease in convective heat transfer resistance as the size of the thermal boundary layer decreased with microscopic size of the channels. It was also found from the simulation results that there was no extra pressure drop at low volume fractions of nanoparticles in the base fluid. The simulation results generated were compared with the analytical data available in the literature and found good agreement.

Scalable High-Performance Ultraminiature Graphene Micro-Supercapacitors by a Hybrid Technique Combining Direct Writing and Controllable Microdroplet Transfer.

Miniaturization of energy storage devices can significantly decrease the overall size of electronic systems. However, this miniaturization is limited by the reduction of electrode dimensions and the reproducible transfer of small electrolyte drops. This paper reports first a simple scalable direct writing method for the production of ultraminiature microsupercapacitor (MSC) electrodes, based on femtosecond laser reduced graphene oxide (fsrGO) interlaced pads. These pads, separated by 2 μm spacing, are 100 μm long and 8 μm wide. A second stage involves the accurate transfer of an electrolyte microdroplet on top of each individual electrode, which can avoid any interference of the electrolyte with other electronic components. Abundant in-plane mesopores in fsrGO induced by a fs laser together with ultrashort interelectrode spacing enables MSCs to exhibit a high specific capacitance (6.3 mF cm-2 and 105 F cm-3) and ∼100% retention after 1000 cycles. An all graphene resistor-capacitor (RC) filter is also constructed by combining the MSC and a fsrGO resistor, which is confirmed to exhibit highly enhanced performance characteristics. This new hybrid technique combining fs laser direct writing and precise microdroplet transfer easily enables scalable production of ultraminiature MSCs, which is believed to be significant for practical application of micro-supercapacitor microelectronic systems.

Dynamic control for safety system multi-agent system with case-based reasoning

The increasing complexity and size of electronic systems in industry, combined with growing market demand, requires industries to implement an efficient safety system to preserve equipment viability, environment protection and especially human life protection. The aim of this paper is to present a dynamic safety system based on a multi-agent paradigm using case-based reasoning to identify and react to risks. To develop the base of cases, an exhaustive risk analysis was carried out, giving rise to risk ontology and their precursors. Then, a model for identifying the similarities between precursors was developed. Case-based reasoning is very reactive, and with the presented model of similarity, the developed security system was very reactive against the risks that the system was experiencing during the experiments.

Dynamic control for safety system multi-agent system with case-based reasoning

The increasing complexity and size of electronic systems in industry, combined with growing market demand, requires industries to implement an efficient safety system to preserve equipment viability, environment protection and especially human life protection. The aim of this paper is to present a dynamic safety system based on a multi-agent paradigm using case-based reasoning to identify and react to risks. To develop the base of cases, an exhaustive risk analysis was carried out, giving rise to risk ontology and their precursors. Then, a model for identifying the similarities between precursors was developed. Case-based reasoning is very reactive, and with the presented model of similarity, the developed security system was very reactive against the risks that the system was experiencing during the experiments.

The Study of the Miniaturisation Effect on the Characteristics of Patch Antenna Using the WCIP Method

The demand of miniature electronic systems has been increasing for several decades. The physical size of systems is reduced due to advancements in integrated circuits. With reduction in size of electronic systems, there is also an increasing demand of small and low cost antennas. Patch antennas are one of the most attractive antennas for integrated RF systems due to their compatibility with microwave integrated circuits. In this paper, the effects of substrate dielectric constant and (...)

Multifunctional oxide nanostructures by metal-organic chemical vapor deposition (MOCVD)

The development of thin films, in the context of ongoing reduction in the size of electronic systems, poses challenging questions for the materials sciences of multifunctional nanostructures. These include the limits of size reduction, integration of heterogeneous functions, and system characterization or process control at an atomic scale. We present here different studies devoted to perovskite oxide materials (or materials with derived structure), where in specific directions of the crystal structure the atomic organization decreases down to a few nanometers, thus building nanostructures. In these materials, very original physical phenomena are observed in multilayers or superlattices, nanowires (NWs) or nanodots, mainly because strain, surfaces, and interfaces play here a predominant role and can tune the physical properties. Metal-organic chemical vapor deposition (MOCVD) routes have been used for the synthesis of oxide materials. We first introduce the basic rules governing the choice of metal-organic precursors for the MOCVD reaction. Next we discuss the principles of the pulsed injection MOCVD system. A laser-assisted MOCVD system, designed to the direct growth of 2D and 3D photonic structures, will also be described. Selected case studies will finally be presented, illustrating the powerful development of different oxide nanostructures based on dielectric, ferroelectric, or superconducting oxides, manganites, and nickelates, as well as first results related to the growth of ZnO NWs.