Stretchable circuit technology, as the name implies, allows an electronic circuit to adapt to its surroundings by elongating when an external force is applied. Based on this, early authors proposed a ...straightforward metric: stretchability-the percentage length increase the circuit can survive while remaining functional. However, when comparing technologies, this metric is often unreliable as it is heavily design dependent. This paper aims to demonstrate this shortcoming and proposes a series of alternate methods to evaluate the performance of a stretchable interconnect. These methods consider circuit volume, material usage, and the reliability of the technology. This analysis is then expanded to the direct current (DC) resistance measurement performed on these stretchable interconnects. A simple dead reckoning approach is demonstrated to estimate the magnitude of these measurement errors on the final measurement.
In a world where great efforts are spent designing and creating more complex, yet efficient systems, sensing elements and related readout circuits, which constitute an integral part of them, need to ...be designed fulfilling these constraints, beside the common key parameters, such as high sensitivity, resolution and accuracy. Capacitive sensors and their differential subset provide virtually no energy dissipation, show insensitivity to temperature variations and have the capability to be micromachined directly onto a silicon substrate, together with the readout interface. Designing a readout circuit that takes advantage of these benefits, according to any specific application, is thus of utmost importance. This volume introduces the reader to state-of- the-art techniques and research achievements in interfacing differential capacitance sensors. Technical topics discussed in the book include: * Switched capacitor based interfaces; * Voltage mode, differential capacitance to time, voltage, digital converters; * Current mode interfaces based on standard components; * Current mode interfaces based on CCIIs and VCIIs; * Principles of second generation current and voltage conveyors. This book gives the reader a comprehensive overview on the working principles, equivalent circuit models and most advanced interfacing techniques for differential capacitive transducers, highlighting benefits and downsides of each option. Electronic Interfaces for Differential Capacitive Sensors is an ideal text for academic staff and Masters/research students in electronic and microelectronic engineering.
Anhand von simulierten Beispielen (kostenlose Software) werden Ampere- und Voltmeter mit ihren Anwendungen und Fehlerquellen erklaert. Das Wattmeter mit Cosinusfunktion bildet die Grundlage der ...praktischen Elektrik und anhand von Messungen werden die Grundfunktionen behandelt. Das Oszilloskop erlaubt die Darstellung von Frequenzen und deren Phasenverschiebung. Auch Versuche mit der Lissajour-Funktion zur Phasen- und Frequenzmessung werden durchgeführt. Für die analoge Technik steht ein universeller Funktionsgenerator zur Verfügung. Für die digitale Elektronik benötigt man einen Logikkonverter, einen Bitmustergenerator und einen Logikanalysator. Nicht nur Hardwareprobleme lassen sich so schnell lösen, wenn man die Fehlerquellen im praktischen Einsatz kennt. Mittels eines Bodeplotters lassen sich zahlreiche RCL-Schaltungen untersuchen. Der Spektrumanalysator mit seinen zahlreichen Funktionen bildet einen Höhepunkt im Messpraktikum. Zum Schluss wird noch das praktischen Arbeiten mit einem Netzwerkanaysator mit seinen zahlreichen Funktionen fuer die Messtechnik behandelt. Das Buch ist für die Weiterbildung der digitalen Industrie 4.0 geeignet.
Ca2Mn3O8 forms a delafossite-related layered structure, which crystallises with monoclinic C2/m symmetry. Compared with the delafossite-structure, the MnO6 layers in Ca2Mn3O8 exhibit an ordered ...cation void which forms a magnetic ‘bow-tie’ like connectivity of Mn4+ ion layers separated by Ca2+ ions. In-situ variable temperature diffraction data demonstrates that the structure is robust up to a temperature of approximately 1173 K before the material decomposes into the perovskite, CaMnO3 and marokite, CaMn2O4 phases. Simultaneous thermal analysis suggests that a very small amount of water remains within the layers post synthesis. Impedance spectroscopy indicates that Ca2Mn3O8 is an electronic conductor in the range ∼400–700 K with an activation energy of 0.50 ± 0.01 eV.
Recently we have pioneered the synthesis of high-quality single phase Ca2Mn3O8. This has allowed us to;•Perform the first variable temperature in-situ powder neutron and x-ray diffraction studies of Ca2Mn3O8 in different atmospheres, allowing us to show that thermal expansion, unusually for a layered material, is largely isotropic.•Report complementary variable temperature Raman spectroscopy studies.•Using Spark Plasma Sintering (SPS) we have been able to prepare high density pellets allowing us to show that Ca2Mn3O8 is an electronic conductor in the range ∼400 – 700 K with an activation energy of 0.50±0.01 eV.
The self-discharge rate is an important parameter to assess the quality of lithium-ion batteries (LIBs). This paper presents an accurate, efficient, and comprehensive method for measuring and ...understanding the self-discharge behaviour of LiB cells, considering factors such as temperature and cell to cell variability, as well as underlying electrochemical mechanisms. A method for precise potentiostatic self-discharge measurement (SDM) is demonstrated that is validated by measuring 21 commercial cylindrical 4.7 Ah cells at a state of charge (SoC) of 30%. The self-discharge current ranges between 3 and 6 μA at 23 °C, with an experimental noise level of 0.25 μA. At higher temperatures of 40 °C the self-discharge current increases to 97 μA. The temperature coefficient of voltage (TCV) is experimentally obtained by exposing the cells to a temperature profile with positive and negative step polarities and following the open circuit voltage (OCV) response. Observed TCVs range from +180 µV/K at 40% SoC to −320 µV/K at 0% SoC. For SDM temperature experiments, the cells were set to an SoC with a minimum TCV. From the SDM currents at different temperatures the Arrhenius kinetics and the electrochemical activation energy barrier is determined as 0.94 ± 0.14 eV, indicating chemical side reactions as source of self-discharge. For SDM modelling the electrochemical processes are coupled with a 3D temperature finite element model (FEM) and an electric circuit model resulting in a good overlap with the dynamics and time-constants of the experimental self-discharge curves. The primary challenges addressed are accurately measuring microampere (µA) discharge currents of high-quality cells, reducing measurement time, understanding the temperature dependence of self-discharge, determining activation energy, and demonstrating the applicability and generalization of SDM.
•A powerful tool is presented to directly measure battery self-discharge.•Precise self-discharge currents are measured with a high resolution of 0.25 µA.•Experimental investigation of the method is done based on temperature and SoC.•Arrhenius analysis of self-discharge provides chemical insights to the LiB cells.•Modified FEM model results in excellent overlap with LiB dynamics and time-constants.
The unclear and unpredictable fracture surface orientations of cortical bones have restricted the deep understanding of fracture mechanisms. The multidirectional loads aggravate the complexity and ...difficulty in the measurement of the fracture surface orientations. This article focused on novel testing instrument and measurement method of the fracture surface orientations of cortical bones. The controllable external loads were realized by a self-developed in situ tester under approximate in vivo environment and various sampling orientations of bone specimens. A normal vector measurement method was proposed to obtain the normal vector of fracture surfaces under various sampling angles. Quantitative variation of fracture surface orientations along with the direction of external loads was obtained. As the sampling angle gradually increased in a range from 0° to 60°, the normal vector angles exhibited a "slow first then fast later" monotonous increasing tendency in a range from 69.18° ± 9.40° to 84.48° ± 9.87°. On the basis of proposed complete fitting method and eliminating abnormal point method, the measurement error of normal vector angle exhibited a slight fluctuation in a range from 0.22% to 1.83%, dependent on the straightness error of intersection line and flatness error of fracture surface. The approximatively invariable propagation distance along the osteon/interstitial lamellae interface and the "bending ductility effect" induced longer propagation distance inside the osteons resulted in the increased normal vector angles of the fracture surfaces when the external loads gradually deviated from the long axis of bones.
The sensitivity of radio receiving devices and systems used in all areas of practical applications of electronics is determined at a certain signal-to-noise ratio value. Examples of systems for which ...this ratio is one of the important quality indicators are given. The objective of the research is to solve the current problem of measuring the signal-to-noise ratio in a wide frequency range, simplify the requirements for measuring instruments, and improve their technical and metrological characteristics. The new principle of measuring the signal-to-noise ratio, which consists in establishing precise connections between this ratio and the parameters of noise amplitude, phase, and frequency signal modulation, is theoretically justified. The validity of using modulation meters as signal-to-noise ratio meters without changing the operation mode has been proven. At that, the signal and noise are not separated and are not measured separately. Precise connections ensure the absence of methodological measurement errors. There are three options for implementing the developed measurement principle using one industrial device (modulation meter) and providing a direct reading of the signal-to-noise ratio. In two of these options there are no restrictions on the origin and type of noise, it may be arbitrary. Taking into account the unambiguous connection between phase and frequency modulation, all options for implementing the considered principle were experimentally tested. The discrepancies between the measurement results and the initial data of the signal and noise generator are within the error limits of the generator instruments. Mathematical simulation of the developed principle for measuring the signal-to-noise ratio in the Mathcad software package has been carried out, and recommendations for using the principle have been given. The fundamental advantages of the proposed principle are its simple implementation using a single industrial device and metrological support for measuring the signal-to-noise ratio. This mode coincides with the main modulation measurement mode. Metrological support for the signal-to-noise ratio measurement mode is carried out within the framework of existing state verification plans. The main technical and metrological characteristics of signal-to-noise ratio meters obtained by applying the considered principle are determined by the parameters of existing modulation meters, i.e. a wide (up to 26 GHz) frequency range and a low (10–20%) measurement error.
Recently, freestanding complex oxide ferroelectric materials have gained attention due to their tremendous potential in electronic and mechanical engineering applications. Whether these materials in ...a freestanding form exhibit intrinsically different behavior than in a strongly bonded as-grown state is a topic of ongoing exploration. Several factors such as circuit configuration, substrates, and electronic measurement conditions can affect probing the intrinsic properties of these materials and complicate the conclusive outcome of such exploration. The importance of maintaining the same experimental conditions for a comparative study of these materials in as-grown and freestanding states is discussed here.
Flexible Electronics platforms are increasingly used in the fields of sensors, displays, and energy conversion with the ultimate goal of facilitating their ubiquitous integration in our daily lives. ...Some of the key advantages associated with flexible electronic platforms are: bendability, lightweight, elastic, conformally shaped, nonbreakable, roll-to-roll manufacturable, and large-area. To realize their full potential, however, it is necessary to develop new methods for the fabrication of multifunctional flexible electronics at a reduced cost and with an increased resistance to mechanical fatigue. Accordingly, this Special Issue seeks to showcase short communications, research papers, and review articles that focus on novel methodological development for the fabrication, and integration of flexible electronics in healthcare, environmental monitoring, displays and human-machine interactivity, robotics, communication and wireless networks, and energy conversion, management, and storage.
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