A New Capacitive Displacement Sensor with High Accuracy and Long-Range",

ABSTRACT A new capacitive displacement sensor is designed and fabricated for measurement of a large displacement with very high accuracy. This sensor is a kind of linear encoder with an array of micro electrodes made by micromachining processes. The two patterned electrodes on the sensor substrates are assembled facing each other after being coated with thin dielectric film. Due to the thin dielectric film, it is highly sensitive to displacement but minimizes expected misalignments such as a tilting error. The sensor fabricated as a sample has a grating of electrodes with a width of 100µm, which is coated with a Diamond-Like Carbon(DLC) film 0.8 µm thick. The proposed sensor was tested to conclude that its resolution is 9.07 nanometers for the measuring range of 15 millimeters and that the linearity error is expected to be less than 0.02% throughout the measurable range

Fabrication of functional micro- and nanoneedle electrodes using a carbon nanotube template and electrodeposition

Carbon nanotube (CNT) is an attractive material for needle-like conducting electrodes because it has high electrical conductivity and mechanical strength. However, CNTs cannot provide the desired properties in certain applications. To obtain micro- and nanoneedles having the desired properties, it is necessary to fabricate functional needles using various other materials. In this study, functional micro- and nanoneedle electrodes were fabricated using a tungsten tip and an atomic force microscope probe with a CNT needle template and electrodeposition. To prepare the conductive needle templates, a single-wall nanotube nanoneedle was attached onto the conductive tip using dielectrophoresis and surface tension. Through electrodeposition, Au, Ni, and polypyrrole were each coated successfully onto CNT nanoneedle electrodes to obtain the desired properties

Improvement of High Dynamic Range Capacitive Displacement Sensor by a Global Planarization

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Fabrication and characterization of 3-Dimensional MOS transistor tip integrated micro cantilever

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Significant Electromechanical Characteristic Enhancement of Coaxial Electrospinning Core–Shell Fibers

Electrospinning is a low-cost and straightforward method for producing various types of polymers in micro/nanofiber form. Among the various types of polymers, electrospun piezoelectric polymers have many potential applications. In this study, a new type of functional microfiber composed of poly(γ-benzyl-α,L-glutamate) (PBLG) and poly(vinylidene fluoride) (PVDF) with significantly enhanced electromechanical properties has been reported. Recently reported electrospun PBLG fibers exhibit polarity along the axial direction, while electrospun PVDF fibers have the highest net dipole moment in the transverse direction. Hence, a combination of PBLG and PVDF as a core–shell structure has been investigated in the present work. On polarization under a high voltage, enhancement in the net dipole moment in each material and the intramolecular conformation was observed. The piezoelectric coefficient of the electrospun PBLG/PVDF core–shell fibers was measured to be up to 68 pC N−1 (d33), and the voltage generation under longitudinal extension was 400 mVpp (peak-to-peak) at a frequency of 60 Hz, which is better than that of the electrospun homopolymer fibers. Such new types of functional materials can be used in various applications, such as sensors, actuators, smart materials, implantable biosensors, biomedical engineering devices, and energy harvesting devices

A Piezoelectric Micro-Cantilever Bio-Sensor Using the Mass-Micro-Balancing Technique with Self-Excitation

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음향 챔버형 마이크로폰 검교정기의 검교정 주파수 한계와 모드 특성을 이용한 개선 방법에 관한 연구

©2022 The Acoustical Society of Korea.This paper identifies the cause of the high frequency calibration limit of the acoustic chamber type calibrator for microphone calibration and presents a method to improve it. By using a commercial finite element analysis software, we analyzed the calibration frequency limit of the acoustic chamber type calibrator through eigen-frequency and frequency domain analysis. Based on this, we designed and fabricated an acoustic chamber type calibrator that can precisely calibrate within 1 dB from about 2 Hz to 6.4 kHz and verified its performance through experiments. The acoustic chamber type calibrator fabricated through this study has the advantage of being able to calibrate multiple microphones simultaneously in a wide frequency range, so it can be usefully used for simple calibration for multiple microphones.Microphone, Microphone calibrator, Sensitivity measurement, Acoustic chamber, Mode shape11Nscopuskc

Capacitive Measurements of SiO2 Films of Different Thicknesses Using a MOSFET-Based SPM Probe

We utilized scanning probe microscopy (SPM) based on a metal-oxide-silicon field-effect transistor (MOSFET) to image interdigitated electrodes covered with oxide films that were several hundred nanometers in thickness. The signal varied depending on the thickness of the silicon dioxide film covering the electrodes. We deposited a 400- or 500-nm-thick silicon dioxide film on each sample electrode. Thick oxide films are difficult to analyze using conventional probes because of their low capacitance. In addition, we evaluated linearity and performed frequency response measurements; the measured frequency response reflected the electrical characteristics of the system, including the MOSFET, conductive tip, and local sample area. Our technique facilitated analysis of the passivation layers of integrated circuits, especially those of the back-end-of-line (BEOL) process, and can be used for subsurface imaging of various dielectric layers

Fabrication and characterization of MOS transistor tip integrated micro cantilever

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