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Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
Sheet resistance - Sheet resistance (or sheet resistivity) is the average resistivity of a layer of material divided by its thickness. If the layer has the same length as width, the resistance between opposite edges of the “square” is numerically equal to the sheet resistance, regardless of the size of the square.
Microelectronic Circuit Enhancements and Design Methodologies to Facilitate Moore’s Law – Part II
Published in Lambrechts Wynand, Sinha Saurabh, Abdallah Jassem, Prinsloo Jaco, Extending Moore’s Law through Advanced Semiconductor Design and Processing Techniques, 2018
Lambrechts Wynand, Sinha Saurabh
Recall that if the resistor geometry is a square, the sheet resistance is specified straightforwardly in Ω. Sheet resistance is typically measured using the four-point probe method, as described in Logan (1967) and Smits (1958). Sheet resistance can be determined theoretically based on the intrinsic properties of the material; however, for certain materials such as InGaAs, InP or InSb, these properties can vary significantly based on physical and electrical external factors such as temperature, power, manufacturing tolerance and uneven distribution through a wafer, and sheet resistance is often measured instead. The following section reviews the techniques used to measure the sheet resistance, Rs, as well as the contact resistance, Rcon, of integrated resistors.
Properties and characterization of conductive polymers
Published in Ze Zhang, Mahmoud Rouabhia, Simon E. Moulton, Conductive Polymers, 2018
David L. Officer, Klaudia Wagner, Pawel Wagner
Sheet resistance (Rs) has units of ohms but is frequently given as ohms per square (Ω/□). This was introduced in 1968 by Berry et al. (1968), where the material dimension term (length/width) was called the number of “squares” in the resistor and was a pure number, having no dimensions. The authors claim that the sheet resistance has the unit of ohms, but it is convenient to refer to it as “ohms per square (Ω/□)” since the sheet resistance produces the resistance of the resistor when multiplied by the number of squares.
Wet chemical method for highly flexible and conductive fabrics for smart textile applications
Published in The Journal of The Textile Institute, 2023
Refik Arat, Guobin Jia, Jonathan Plentz
The structural, morphological and conductivity properties of the conductive fabric were examined. The X-ray diffraction (XRD) patterns were recorded by XPERT-PRO diffractometer using Cu-Kα1 radiation with λ = 1.5406 Å. The scanning electron microscopy (SEM) images and optical micrographs were taken by FEI Helios NanoLab G3 UC/ThermoFisher Scientific and Zeiss Axiotech 100 HD microscope, respectively. The sheet resistance (Rs) values were measured by a four-point probe conductivity test meter (SMU238, Keithley). During the bending test, the Rs values were measured by a precision multi-meter (ISO-TECH, LCR-1701). FTIR analysis of the synthesized ZnO particles was performed with a Thermo Scientific Nicolet iS10 FTIR-spectrometer in the wavenumber range of 4000–400 cm−1 with a 2 cm−1 resolution.
Reduced graphene oxide coated cotton e-textile for wearable chemical warfare agent sensors
Published in Advanced Composite Materials, 2022
Dongwon Ka, Keunhong Jeong, Youngho Jin
Scanning electron microscopy (SEM; JSM-IT500HR, JEOL Ltd., Tokyo, Japan) was performed at an accelerating voltage of 5 kV. X-ray photoelectron spectroscopy (XPS) was performed using a K-alpha+ (Thermo Scientific, MA, USA) instrument. Thermogravimetric analysis (TGA) was used to study the thermal stability of GO and rGO using a thermogravimetric analyzer (Q500, TA Instruments, Newcastle, PA, USA). A Fourier-transform infrared (FTIR) spectrometer (Thermo Scientific, Nicolet i50, Swedesboro, NJ, USA) with a DiffusIR accessory was used for conducting diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The sheet resistance was measured using a Keithley 2401source meter (Tektronix, OR, USA) and a four-point probe station with a probe spacing of 1 mm. Impedance spectroscopy (Solartron 1260, Ametek Inc., PA, USA) and dielectric interface (Solartron 1296) were used to characterize the impedance of the rGO fabric. The real and imaginary impedance values were obtained at frequencies ranging from 10 MHz–1 Hz using an alternating current (AC) voltage of 500 mV.
Chinese ink-facilitated fabrication of paper-based composites as electrodes for supercapacitors
Published in International Journal of Smart and Nano Materials, 2021
Weili Yan, Zhuohao Xiao, Xiuying Li, Xiang Wu, Ling Bing Kong
The sheet resistance of the composite sheets was measured by using the four-probe method, with an automatic-mapping four-point-probe system (Materials Development Corporation, Model CMT-SR2000N) at room temperature. The tested samples were placed onto a glass slide as the probes may penetrate the sheets and give false results. For each sample, nine even-distributed points were tested to get an average value.