scholarly journals A Novel Capacitive Sensing Principle for Microdevices

2015 ◽  
Author(s):  
Jian Zhou ◽  
Ronald N. Miles ◽  
Shahrzad Towfighian
Keyword(s):  
Electric Field ◽  
Driving Force ◽  
Design Principle ◽  
Electrostatic Force ◽  
Low Cost ◽  
Repulsive Force ◽  
Attractive Force ◽  
Sensor Design ◽  
Capacitive Sensing

Conventional capacitive sensing places significant limitations on the sensor design due to the pull-in instability caused by the electrostatic force. The main purpose of this study is to examine a low-cost novel capacitive sensing principle based on electrostatic balance which promises to avoid these design limitations. The approach uses an asymmetric electric field on a structure with fingers that can generate a repulsive force while the gap is low and create an attractive force while the gap is large. The size and thickness of the fingers are also responsible for creating repulsive or attractive forces on the structure. This approach has recently been applied successfully in the design of capacitive actuators to provide a repulsive driving force. A new design principle for capacitive sensing is described that avoids pull-in instability by designing the fingers such that the structure is at the equilibrium.

A New Design of Large Stroke Micro-Deformable Mirror Actuated by Electrostatic Repulsive Force

2008 ◽  
Author(s):  
Fangrong Hu ◽  
Jun Yao ◽  
Chuankai Qiu ◽  
Dajia Wang
Keyword(s):  
Electric Field ◽  
Resonant Frequency ◽  
Adaptive Optics ◽  
Bottom Electrode ◽  
Sacrificial Layer ◽  
Electrostatic Force ◽  
Repulsive Force ◽  
Deformable Mirror ◽  
Optical Aberrations ◽  
Out Of Plane

In this paper, a MEMS mirror actuated by an electrostatic repulsive force has been proposed and analyzed. The mirror consists of four U-shape springs, a fixed bottom electrode and a movable top electrode, there are many comb fingers on the edges of both electrodes. When the voltage is applied to the top and bottom electrodes, an asymmetric electric field is generated to the top movable fingers and springs, thus a net electrostatic force is produced to move the top plate out of plane. This designed micro-mirror is different from conventional MDM based on electrostatic-attractive-force, which is restricted by one-third thickness of the sacrificial layer for the pull-in phenomenon. The characteristic of this MDM has been analyzed, the result shows that the resonant frequency of the first mode is 8 kHz, and the stroke reaches 10μm at 200V, a MDM with large strokes can be realized for the application of adaptive optics in optical aberrations correction.

scholarly journals Reinterpretation of Electric Field with Quantum Fluctuations: The Mechanism of Electrostatic Force of Attraction and Repulsion Between Two Point Charges

2020 ◽  
pp. 28-33
Author(s):  
C. G. Sim
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Vacuum Polarization ◽  
Quantum Fluctuation ◽  
Casimir Effect ◽  
Electrostatic Force ◽  
Quantum Fluctuations ◽  
Repulsive Force ◽  
Fluctuation Energy ◽  
Virtual Pairs

Vacuum polarization rearranges virtual  pairs. This causes the virtual  pairs to rigidify in vacuum, reducing the quantum fluctuation energy. The quantum fluctuation energy is a fundamental force of vacuum, as evidenced by the Casimir effect. The change in quantum fluctuation energy was simulated in the superposition of the electric fields. The results show that the increase and decrease of the quantum fluctuation energy between the two point charges is related to the repulsive force and attraction in Coulomb's law.

Fluctuation of Position and Energy of a Fine Particle in Plasma Nanofabrication

2016 ◽  
Vol 879 ◽  
pp. 1772-1777 ◽  
Author(s):  
Masaharu Shiratani ◽  
Masahiro Soejima ◽  
Hyun Woong Seo ◽  
Naho Itagaki ◽  
Kazunori Koga
Keyword(s):  
Optical Tweezers ◽  
Fine Particle ◽  
Fine Particles ◽  
Electrostatic Force ◽  
Repulsive Force ◽  
Attractive Force ◽  
Coulomb Collision ◽  
Optical Forces ◽  
Ion Collisions ◽  
Guided Assembly

We are developing plasma nanofabrication, namely, nanoand micro scale guided assembly using plasmas. We manipulate nanoand micro objects using electrostatic, electromagnetic, ion drag, neutral drag, and optical forces. The accuracy of positioning the objects depends on fluctuation of position and energy of a fine particle (= each object) in plasmas. Here we evaluate such fluctuations and discuss the mechanism behind them. In the first experiment, we grabbed a fine particle in plasma using an optical tweezers. The fine particle moves in a potential well made by the optical tweezers. This is a kind of Brownian motion and the position fluctuation can be caused by neutral molecule collisions, ion collisions, and fluctuation of electrostatic force. Among theses possible causes, fluctuation of electrostatic force may be main one. In the second experiment, we deduced interaction potential between two fine particles during their Coulomb collision. We found that there exist repulsive and attractive forces between them. The repulsive force is a screened Coulomb one, whereas the attractive force is likely a force due to a shadow effect, a non-collective attractive force. Moreover, we noted that there is a fluctuation of the potential, probably due to fluctuation of electrostatic force. These position and potential energy fluctuations may limit the accuracy of guided assembly using plasmas.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

Driving Force Behind the O-Rh(001) Clock Reconstruction

1998 ◽  
Vol 12 (20) ◽  
pp. 849-857 ◽  
Author(s):  
Chang Q. Sun
Keyword(s):  
Driving Force ◽  
Electrostatic Force ◽  
Bond Formation ◽  
Lone Pair ◽  
Atomic Ratio ◽  
Recent Model ◽  
Dual Roles ◽  
Low Energy Electron Diffraction ◽  
Dipole Interactions ◽  
Low Energy Electron

A novel rhombi-chain network is derived from low energy electron diffraction experimental observations and the recent model theory, revealing that the O-Rh(100) clock-rotation is driven by an electrostatic force arisen from bond formation. Thus the O-Rh bond suffers from tension other than compression, or strain relief. As O -1 evolves into the hybridized- O -2,a Rh 5 O cluster in the c(2 × 2) phase develops into a Rh 4 O tetrahedron and yields the overall (2 × 2)p4g reconstruction. In the (2 × 2)p4g phase, the hollow-sited O -2 defines one Rh + ion and two lone-pair-induced Rh dipoles of its four surface neighbors. The surface atomic ratio (O : Rh = 1 : 2) allocates, therefore, half of the surface Rh atoms to be the Rh dipoles and another half to play dual roles of Rh + ion and Rh dipole. Interactions along the "dipole–dipole – Rh +/dipole – Rh +/dipole" strings create the rhombi-chain at the <11> directions, and a responding bond tension confines the (2 × 2)p4g clock rotation.

Electrostatic Forces on Particles Floating Within the Interface Between Two Immiscible Fluids

2007 ◽  
Author(s):  
Nadine Aubry ◽  
Pushpendra Singh
Keyword(s):  
Dielectric Properties ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
External Electric Field ◽  
Capillary Force ◽  
Electrostatic Force ◽  
Immiscible Fluids ◽  
Electrostatic Forces ◽  
Dipole Interactions

The objective of this paper is to study the dependence of the electrostatic force that act on a particle within the interface between two immiscible fluids on the parameters such as the dielectric properties of the fluids and particles, the particle’s position within the interface, and the electric field strength. It is shown that the component of electrostatic force normal to the interface varies as a2, where a is the particle radius, and since in equilibrium it is balanced by the vertical capillary force, the interfacial deformation caused by the particle changes when an external electric field is applied. In addition, there are lateral electrostatic forces among the particles due to the dipole-dipole interactions which, when the distance between two particles is O(a), vary as a2, and remain significant for submicron sized particles.

scholarly journals A low-cost, human-like, high-resolution, tactile sensor based on optical fibers and an image sensor

2018 ◽  
Vol 15 (4) ◽  
pp. 172988141878363 ◽  
Author(s):  
Utku Büyükşahin ◽  
Ahmet Kırlı
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Fiber Optic ◽  
Low Cost ◽  
Experimental Studies ◽  
Main Idea ◽  
Tactile Sensor ◽  
Image Sensor ◽  
Sensor Design ◽  
Tactile Sensors

Tactile sensors are commonly a coordinated group of receptors forming a matrix array meant to measure force or pressure similar to the human skin. Optic-based tactile sensors are flexible, sensitive, and fast; however, the human fingertip’s spatial resolution, which can be regarded as the desired spatial resolution, still could not be reached because of their bulky nature. This article proposes a novel and patented optic-based tactile sensor design, in which fiber optic cables are used to increase the number of sensory receptors per square centimeter. The proposed human-like high-resolution tactile sensor design is based on simple optics and image processing techniques, and it enables high spatial resolution and easy data acquisition at low cost. This design proposes using the change in the intesity of the light occured due to the deformation on contact/measurement surface. The main idea is using fiber optic cables as the afferents of the human physiology which can have 9 µm diameters for both delivering and receiving light beams. The variation of the light intensity enters sequent mathematical models as the input, then, the displacement, the force, and the pressure data are evaluated as the outputs. A prototype tactile sensor is manufactured with 1-mm spatial and 0.61-kPa pressure measurement resolution with 0–15.6 N/cm2 at 30 Hz sampling frequency. Experimental studies with different scenarios are conducted to demonstrate how this state-of-the-art design worked and to evaluate its performance. The overall accuracy of the first prototype, based on different scenarios, is calculated as 93%. This performance is regarded as promising for further developments and applications such as grasp control or haptics.

scholarly journals Sludge water stabilization treatment

2021 ◽  
Vol 303 ◽  
pp. 01048
Author(s):  
Elena Murko ◽  
Vasily Murko ◽  
Jurgen Kretchmann
Keyword(s):  
Electric Field ◽  
Organic Contaminants ◽  
Low Cost ◽  
Coal Industry ◽  
Solid Particles ◽  
Recycled Water ◽  
Flotation Reagents ◽  
Stabilization Treatment ◽  
Industrial Enterprises ◽  
Service Water

Technologically contaminated water, formed during processing of coal slurries, finds its application in modern technological cycles of coal enrichment. Limitation of use of untreated recycled water of coal concentration plants is caused by a high degree of its mineralization by various salts, presence of insoluble solid particles and presence of flotation reagents, coagulants and flocculants. Part of technical water purified from mineral and organic contaminants can be used in heating systems and heat exchange equipment of industrial enterprises, including the coal industry. For this purpose, it is necessary to reduce the scale-forming ability of service water (to reduce the content of soluble calcium and magnesium salts in water). One of the most effective and advanced methods is the stabilization treatment of water with an electric field. In addition, this method is environmentally safe, low-cost and simple. The article gives the foundation of the method of stabilization treatment of recycled water of concentrating plants by an electric field, a description of the methodology of the laboratory experiment for scaling reduction, and the analysis of the results.

scholarly journals Study of Chromium Removal by the Electrodialysis of Tannery and Metal-Finishing Effluents

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Ruan C. A. Moura ◽  
Daniel A. Bertuol ◽  
Carlos A. Ferreira ◽  
Franco D. R. Amado
Keyword(s):  
Wastewater Treatment ◽  
Ion Exchange ◽  
Electric Field ◽  
Driving Force ◽  
Membrane Separation ◽  
Physicochemical Process ◽  
Separation Technique ◽  
Chromium Removal ◽  
Metal Finishing ◽  
Interesting Alternative

The metal-finishing and tannery industries have been under strong pressure to replace their current wastewater treatment based on a physicochemical process. The electrodialysis process is becoming an interesting alternative for wastewater treatment. Electrodialysis is a membrane separation technique, in which ions are transported from one solution to another through ion-exchange membranes, using an electric field as the driving force. Blends of polystyrene and polyaniline were obtained in order to produce membranes for electrodialysis. The produced membranes were applied in the recovery of baths from the metal-finishing and tannery industries. The parameter for electrodialysis evaluation was the percentage of chromium extraction. The results obtained using these membranes were compared to those obtained with the commercial membrane Nafion 450.

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