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Czy jest możliwe wykorzystanie sieci 2G/GPRS do konstrukcji urządzenia IOT o niskim poborze baterii i długim czasie pracy na jednym ładowaniu akumulatora? Powyższe zostało przeanalizowane na bazie lokalizatora notiOne GPS. W artykule wymieniono wykorzystane elementy i ich wpływ na finalne zużycie energii. Pokazano również jak zarządzać modułem GPRS, aby maksymalnie wydłużyć czas pracy urządzenia.&nbsp

With the development of microelectronic devices having miniaturized and integrated electronic components, an efficient thermal management system with lightweight materials, which have outstanding thermal conductivity and processability, is becoming increasingly important. Recently, the use of polymer-based thermal management systems has attracted much interest due to the intrinsic excellent properties of the polymer, such as the high flexibility, low cost, electrical insulation, and excellent processability. However, most polymers possess low thermal conductivity, which limits the thermal management applications of them. To address the low thermal conduction of the polymer materials, many kinds of thermally conductive fillers have been studied, and the carbon-based polymer composite is regarded as one of the most promising materials for the thermal management of the electric and electronic devices. In addition, the next generation electronic devices require composite materials with various additional functions such as flexibility, low density, electrical insulation, and oriented heat conduction, as well as ultrahigh thermal conductivity. In this review, we introduce the latest papers on thermally conductive polymer composites based on carbon fillers with sophisticated structures to meet the above requirements. The topic of this review paper consists of the following four contents. First, we introduce the design of a continuous three-dimensional network structure of carbon fillers to reduce the thermal resistance between the filler–matrix interface and individual filler particles. Second, we discuss various methods of suppressing the electrical conductivity of carbon fillers in order to manufacture the polymer composites that meet both the electrical insulation and thermal conductivity. Third, we describe a strategy for the vertical alignment of carbon fillers to improve the through-plane thermal conductivity of the polymer composite. Finally, we briefly mention the durability of the thermal conductivity performance of the carbon-based composites. This review presents key technologies for a thermal management system of next-generation electronic devices.

The study reported in this paper aimed to investigate the response of a GAFChromic? HD-V2 film dosimeter in the dose range between 10 and 300 Gy, normally used to perform irradiation tests on electronic devices with a 60Co gamma-ray irradiator. The well-defined linearity of response in terms of absorbance as a function of absorbed dose, easiness of handling and data analysis of irradiated dosimeters, reproducibility, stability, and insensitivity to visible light and most of the environmental parameters, make HD-V2 film a flexible, inexpensive and reliable dose measurement device. The study has shown a fogging effect of the dosimeter response since its value changes over time. Strategies and adequate precautions to take into account changes on HD-V2 film physical properties for calibration and routine use in industrial applications, with a specific reference to radiation testing of electronic devices, have been discussed.

The article considers the method of thermal stabilization for precision power supply output voltage by means of anisotropy of the construction thermal field. Interdependency between schematic and design-topological aspects of precision power supply temperature assurance is shown. In theoretical part of the paper, the concept of electronic component local group arranged on isothermal line of the supporting structure plane is introduced. The local group characteristics and conditions for ensuring topological thermocompensation are formulated. The authors propose the solution for two basic applied problems that provides temperature stabilization of electronic devices output parameters by topological temperature compensation using regression analysis. The experimental part of the paper provides the analysis of the output voltage temperature stability for two design versions which differ by availability of topological thermocompensation. The reason of foreign element base use for the purposes of the experimental part of the study is explained. It is shown that the global mathematical model for providing topological thermocompensation for a design option with improved temperature stability is the temperature error equation. A comparative analysis of the two construction options shows 8 % improvement of output voltage temperature stability due to topological thermocompensation. The obtained result may prove to be satisfactory under technical assignment for the use of a different element base and / or other methods of thermal stabilization.

Objective: This study aimed to evaluate the television (TV) viewing and computer and mobile phone usage duration in a community sample of Chinese adults and examine their associations with BMI and obesity.Methods: We conducted a community-based health needs assessment study from February to December 2018 among 2,873 Chinese adults in Nanshan District of Shenzhen, China. We used self-administered questionnaires to collect the data from 24 community health service centers in Nanshan District. The participants individually recorded the time they spent watching TV and using computers and mobile phones. They also answered questions about their sociodemographic and lifestyle factors. We measured their height and weight by using ultrasonic height and weight scales. Then, we calculated and categorized their BMI in accordance with the standards prescribed by the World Health Organization for Asians.Results: Most of the participants were young adults (aged 18–44 years, 74.2%). The overall prevalence of obesity was 15.30%. The prevalence of TV, computer, and mobile phone usage was 75.5, 71.2, and 93.8% in females and 71.1, 75.7, and 94.2% in males, respectively. The youth (18–24 years) and the elderly (65 years or older) had the longest time using mobile phones (3.78 ± 2.51 h) and watching TV programs (2.12 ± 1.38 h), respectively. Longer usage of computers and mobile phones was evident in males (p < 0.05) and participants with a high education level (p < 0.01). The univariate analysis results showed an association between high BMI and obesity and short duration of using computers and mobile phones (all p < 0.05). By contrast, no significant associations were found between the length of TV program viewing and mobile phone usage and BMI (p > 0.05). After we adjusted for potential confounders, we found that computer usage time and the overall usage time of the three electronic devices had an inverse association with BMI (p < 0.05).Conclusions: Mobile phones were the most popular electronic device in Nanshan residents of Shenzhen. Unlike most previous studies, we found an inverse association between screen time and BMI. Nevertheless, scholars should conduct further studies to explore this association. Overall, we strongly encourage the appropriate use of electronic devices.

The methodology, developed for active testing of electronic devices under the radiations, is presented. The test set-up includes a gamma-ray facility, the hardware board/fixtures and the software tools purposely designed and realized. The methodology is so wide-ranging to allow us the verification of different classes of electronic devices, even if only application examples for static random access memory modules are reported.

Increasing attention has been paid to the next generation of ‘green’ electronic devices based on renewable nanocellulose, owing to its low roughness, good thermal stability and excellent optical properties. Various proof-of-concept transparent nanopaper-based electronic devices have been fabricated; these devices exhibit excellent flexibility, bendability and even foldability. In this review, we summarize the recent progress of transparent nanopaper that uses different types of nanocellulose, including pure nanocellulose paper and composite nanocellulose paper. The latest development of transparent and flexible nanopaper electronic devices are illustrated, such as electrochromic devices, touch sensors, solar cells and transistors. Finally, we discuss the advantages of transparent nanopaper compared to conventional flexible plastic substrate and the existing challenges to be tackled in order to realize this promising potential. NRF (Natl Research Foundation, S’pore) Published version

The reference electronic skin is a sensor array based on PVDF (Polyvinylidene fluoride) piezoelectric polymers, coupled to a rigid substrate and covered by an elastomer layer. It is first evaluated how a distributed normal force (Hertzian distribution) is transmitted to an extended PVDF sensor through the elastomer layer. A simplified approach based on Boussinesq’s half-space assumption is used to get a qualitative picture and extensive FEM simulations allow determination of the quantitative response for the actual finite elastomer layer. The ultimate use of the present model is to estimate the electrical sensor output from a measure of a basic mechanical action at the skin surface. However this requires that the PVDF piezoelectric coefficient be known a-priori. This was not the case in the present investigation. However, the numerical model has been used to fit experimental data from a real skin prototype and to estimate the sensor piezoelectric coefficient. It turned out that this value depends on the preload and decreases as a result of PVDF aging and fatigue. This framework contains all the fundamental ingredients of a fully predictive model, suggesting a number of future developments potentially useful for skin design and validation of the fabrication technology.

Automated control systems employ electronic components that are connected with a printed circuit board (PCB) by soldered joints. At elevated temperatures and with high vibration levels, soldering defects may occur that are characterized by the deterioration or complete loss of contact with the PCB, which can lead to the failure of the system. In this work, an approach is proposed to considerably improve the reliability of soldered joints. © 2013 Pleiades Publishing, Ltd.

Memory is a prerequisite for many electronic devices. Organic non-volatile memory devices based on ferroelectricity are a promising approach towards the development of a low-cost memory technology based on a simple cross-bar array. In this review article we discuss the latest developments in this area with a focus on the most promising opto-electronic device concept, i.e., bistable rectifying diodes. The integration of these diodes into larger memory arrays is discussed. Through a clever design of the electrodes we demonstrate light emitting diodes with integrated built-in switches that can be applied in signage applications. © 2011 Elsevier Ltd.

The breakdown behavior of electronics exposed to single transient electromagnetic pulses is subject of investigations for several years. State-of-the-art pulse generators additionally provide the possibility to generate pulse sequences with variable pulse repetition rate. In this article the influence of this repetition rate variation on the breakdown behavior of electronic systems is described. For this purpose microcontroller systems are examined during line-led exposure to pulses with repetition rates between 1 KHz and 100 KHz. Special attention is given to breakdown thresholds and breakdown probabilities of the electronic devices.

Under the terms of the Creative Commons Attribution (CC BY) license to their work., While graphene-based technology shows great promise for a variety of electronic applications, including radio-frequency devices, the resistance of the metal-graphene contact is a technological bottleneck for the realization of viable graphene electronics. One of the most important factors in determining the resistance of a metal-graphene junction is the contact resistivity. Despite the large number of experimental works that exist in the literature measuring the contact resistivity, a simple model of it is still lacking. In this paper, we present a comprehensive physical model for the contact resistivity of these junctions, based on the Bardeen Transfer Hamiltonian method. This model unveils the role played by different electrical and physical parameters in determining the specific contact resistivity, such as the chemical potential of interaction, the work metal-graphene function difference, and the insulator thickness between the metal and graphene. In addition, our model reveals that the contact resistivity is strongly dependent on the bias voltage across the metal-graphene junction. This model is applicable to a wide variety of graphene-based electronic devices and thus is useful for understanding how to optimize the contact resistance in these systems., We acknowledge support from SAMSUNG within the Global Innovation Program. The research leading to these results has received funding from Ministerio of Economía y Competitividad of Spain under the Project Nos. TEC2012-31330 and MAT2012-33911, and from the European Union Seventh Framework Programme under Grant Agreement No. 604391 Graphene Flagship.

Inkjet printing is a promising approach towards the solution processing of electronic devices on an industrial scale. Of particular interest is the production of high-end applications such as large area OLEDs on flexible substrates. Roll-to-roll (R2R) processing technologies involving inkjet printing have especially high potential, since they allow a continuous production of large volumes with high throughput. Here we report on our research activities to scale up printed OLED production on foils to an industrial scale. When building up the device, necessarily deposition will have to be done on very different types of surfaces, some of which are highly prone to damage upon mechanical load. Inkjet printing as a non-impact technology is therefore expected to have decisive advantages compared to e. g. screen printing. We have evaluated both methods for silver shunt line deposition on a barrier layer which protects the OLED against humidity. Screen printing on the barrier layer resulted in a significantly higher number of defects than did inkjet printing. For post-deposition treatment we have used photonic flash sintering as a highly efficient and R2R compatible method. We were thus able to demonstrate that a core step of OLED production can be carried out by R2R processing. Finally, our efforts resulted in the production of fully functional large area OLED devices, with inkjet printed silver shunt lines. Our future plans include moving towards fully integrated R2R production of OLEDs to demonstrate this concept's feasibility for industrial scale manufacturing. cop. 2014 Society for Imaging Science and Technology.

Electrically conductive structures comprising both narrow line widths and high aspect ratios are indispensable components of many electronic devices. Producing them reliably on an industrial scale by inkjet printing of metal-based inks is a serious challenge. Firstly, due to spreading of the ink on the substrate, widths of 30 microns are currently the limit of any standard industrial inkjet technology. Secondly, the solid loads of conductive inkjet fluids are usually confined to a low volume fraction. Consequently, fine and high conductive structures are difficult to reach with single pass printing approaches. Here we report on a method which circumvents these limits by employing specific changes in the ink-substrate interactions during solvent evaporation. Freshly printed lines have widths in the order of 100 microns. Upon drying, these structures reproducibly shrink to very narrow (< 25 micron), though still continuous and highly conductive lines with heights of several microns. This results in aspect ratios of up to 0.3, which are unprecedented for single pass inkjet printing. We propose a mechanism for this process which involves the sequential evaporation of the ink's solvents according to their vapour pressures. Since their volatilities correspond inversely with their respective polarities, the effective polarity of the material remaining on the substrate will continuously increase. A continuous movement out of the wetting envelope of the substrate is the logical consequence, resulting in ever poorer wetting, increasing contact angles and line shrinkage. cop. 2014 Society for Imaging Science and Technology.

Under severe service conditions of electronic instruments (at elevated temperatures and vibrations in electronic systems), failures in their operation frequently occur. Severe intrinsic thermal conditions of operating instruments may cause such failures. However, malfunctions in electronic devices may often be due to defects in soldered joints that were made at lowered temperatures. An approach is proposed that makes it possible to considerably improve the reliability of soldered joints. © 2013 Pleiades Publishing, Ltd.

The challenge of lithographic production of electronic circuitry on polymer foil is that deformations approaching the feature sizes of the circuitry can cause considerable overlay problems and thereby malfunctioning of the devices. The substrate foil is susceptible to several types of deformations. Accurate prediction of these deformations is of great importance, as it will help to improve the production process and thereby improve the quality of the electronic devices. One of the deformations is the residual shrinkage, a deformation that occurs after application of a heat step to a polymer foil. This study presents an experimental investigation of residual shrinkage combined with a modeling approach in which the temperature dependent visco-elastic material properties of the foil are used. The model enables us to more accurately predict overlay errors. ©2010 IEEE.

The challenge of lithographic production of electronic circuitry on polymer foil is that deformations approaching the feature sizes of the circuitry can cause considerable overlay problems and thereby malfunctioning of the devices. The substrate foil is susceptible to several types of deformations. Accurate prediction of these deformations is of great importance, as it will help to improve the production process and thereby improve the quality of the electronic devices. One of the deformations is the residual shrinkage, a deformation that occurs after application of a heat step to a polymer foil. This study presents an experimental investigation of residual shrinkage combined with a modeling approach in which the temperature dependent visco-elastic material properties of the foil are used. The model enables us to more accurately predict overlay errors. ©2010 IEEE.

Inkjet printing is a promising approach towards the solution processing of electronic devices on an industrial scale. Of particular interest is the production of high-end applications such as large area OLEDs on flexible substrates. Roll-to-roll (R2R) processing technologies involving inkjet printing have especially high potential, since they allow a continuous production of large volumes with high throughput. Here we report on our research activities to scale up printed OLED production on foils to an industrial scale. When building up the device, necessarily deposition will have to be done on very different types of surfaces, some of which are highly prone to damage upon mechanical load. Inkjet printing as a non-impact technology is therefore expected to have decisive advantages compared to e. g. screen printing. We have evaluated both methods for silver shunt line deposition on a barrier layer which protects the OLED against humidity. Screen printing on the barrier layer resulted in a significantly higher number of defects than did inkjet printing. For post-deposition treatment we have used photonic flash sintering as a highly efficient and R2R compatible method. We were thus able to demonstrate that a core step of OLED production can be carried out by R2R processing. Finally, our efforts resulted in the production of fully functional large area OLED devices, with inkjet printed silver shunt lines. Our future plans include moving towards fully integrated R2R production of OLEDs to demonstrate this concept's feasibility for industrial scale manufacturing. cop. 2014 Society for Imaging Science and Technology.

Electrically conductive structures comprising both narrow line widths and high aspect ratios are indispensable components of many electronic devices. Producing them reliably on an industrial scale by inkjet printing of metal-based inks is a serious challenge. Firstly, due to spreading of the ink on the substrate, widths of 30 microns are currently the limit of any standard industrial inkjet technology. Secondly, the solid loads of conductive inkjet fluids are usually confined to a low volume fraction. Consequently, fine and high conductive structures are difficult to reach with single pass printing approaches. Here we report on a method which circumvents these limits by employing specific changes in the ink-substrate interactions during solvent evaporation. Freshly printed lines have widths in the order of 100 microns. Upon drying, these structures reproducibly shrink to very narrow (< 25 micron), though still continuous and highly conductive lines with heights of several microns. This results in aspect ratios of up to 0.3, which are unprecedented for single pass inkjet printing. We propose a mechanism for this process which involves the sequential evaporation of the ink's solvents according to their vapour pressures. Since their volatilities correspond inversely with their respective polarities, the effective polarity of the material remaining on the substrate will continuously increase. A continuous movement out of the wetting envelope of the substrate is the logical consequence, resulting in ever poorer wetting, increasing contact angles and line shrinkage. cop. 2014 Society for Imaging Science and Technology.