A new floating electrode structure for generating homogeneous electrical fields in microfluidic channels

Lab on a Chip ◽  
2011 ◽  
Vol 11 (12) ◽  
pp. 1995 ◽  
Author(s):  
Loes I. Segerink ◽  
Ad J. Sprenkels ◽  
Johan G. Bomer ◽  
Istvan Vermes ◽  
Albert van den Berg
Keyword(s):  
Microfluidic Channels ◽  
Electrode Structure ◽  
Electrical Fields ◽  
Floating Electrode

Switching Behavior in a Vertical Tunneling Transistor by Tunneling Mechanism Transition and Floating Electrode Structure

2020 ◽  
Vol 2 (8) ◽  
pp. 2461-2469
Author(s):  
Jeong Hee Shin ◽  
Su Jin Heo ◽  
Jae Hoon Yang ◽  
Hyun Sik Kim ◽  
Jae Eun Jung ◽  
...  
Keyword(s):  
Switching Behavior ◽  
Electrode Structure ◽  
Tunneling Mechanism ◽  
Mechanism Transition ◽  
Floating Electrode

Bimorph Diaphragm Formed by Two PZT Sheets on Micromachined Silicon for Sound Generation

2010 ◽  
Vol 2010 (DPC) ◽  
pp. 001887-001905
Author(s):  
Youngki Choe ◽  
Shih-Jui Chen ◽  
Eun Sok Kim
Keyword(s):  
Sound Pressure ◽  
Pressure Level ◽  
Laser Vibrometer ◽  
Acoustic Intensity ◽  
Electrical Fields ◽  
Low Viscosity ◽  
Sinusoidal Input ◽  
Floating Electrode ◽  
Driving Signal ◽  
Measurement Area

This paper describes a microspeaker (composed of a mechanically-polished PZT bimorph diaphragm and bulk-micromachined silicon top cover) that shows flat diaphragm displacement from DC to 16kHz. A bimorph diaphragm is formed by gluing two 127μm thick PZT sheets and attaching them to a micromachined silicon substrate. The front-side pre-deposited nickel electrode was patterned to maximize the stress distribution over a diaphragm with its four edges clamped, when it goes through bending displacement. With un-patterned floating electrode on one side of the diaphragm, the PZT bimorph can generate stresses with opposite signs along the thickness direction without the need of fine alignment among the electrode patterns. It is important to reduce the thickness of the glue layer between the two PZT sheets, in order to maximize the electrical fields inside the PZT sheets, since the glue layer takes some of the applied voltage away. With mechanical polishing and spin-coating of low viscosity resin epoxy, we have been able to reduce the glue layer thickness to about 1 μm with variation less than 0.5 μm from a typical 25μm thickness. The microspeaker with an encapsulating cylindrical package of about 0.5 cc inside volume produces sound pressure level (SPL) of 103.6 ~ 110 dB between 1.3 and 12 kHz when measured 5 mm away from the diaphragm with 190Vpeak-to-peak driving signal. The measured SPL drops as the frequency is reduced below 1 kHz, due to increasing wavelength and thus reduced total acoustic intensity over the measurement area. The diaphragm was measured (with a laser vibrometer) to produce uniform displacement from DC to 16kHz. With 190Vpeak-to-peak sinusoidal input, the displacement at the center of the diaphragm was measured to have 1.86μm displacement at the fundamental resonant frequency of 16.2 kHz.

Electrokinetics in Microfluidic Channels Containing a Floating Electrode

2008 ◽  
Vol 130 (32) ◽  
pp. 10480-10481 ◽  
Author(s):  
Rahul Dhopeshwarkar ◽  
Dzmitry Hlushkou ◽  
Mark Nguyen ◽  
Ulrich Tallarek ◽  
Richard M. Crooks
Keyword(s):  
Microfluidic Channels ◽  
Floating Electrode

scholarly journals A Novel Mass-Producible Capacitive Sensor with Fully Symmetric 3D Structure and Microfluidics for Cells Detection

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 325
Author(s):  
Zhaorui Zuo ◽  
Kun Wang ◽  
Libin Gao ◽  
Vincent Ho ◽  
Hongju Mao ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Cell Concentration ◽  
3D Structure ◽  
Capacitive Sensor ◽  
Test System ◽  
Microfluidic Channels ◽  
Cell Detection ◽  
Transfer Program ◽  
Electrode Structure ◽  
Capacitance Change

Affinity biosensors of interdigitated electrodes have been widely used in cell detection. This research presents a mass-producible and disposable three-dimensional (3D) structure capacitive sensor based on the integrated circuit package lead frames for cell concentration detection. The fully symmetric 3D interdigital electrode structure makes the sensor more homogeneous and sensitive. (3-Aminopropyl) triethoxysilane (APTES) and glutaraldehyde are immobilized onto gold-plated electrodes. By overlaying the microfluidic channels on top, the volume of the solution is kept constant to obtain repeatable measured capacitance values. Moreover, using the upgraded reading and writing functions and circular measurement of the E4980A Data Transfer Program, an automatic multigroup test system is developed. It is shown that the cell concentration and capacitance are inversely correlated, and the cell concentration range of 103–106 CFU∙mL−1 is achieved. In addition, the rate of capacitance change matches that of state-of-the-art biosensors reported. A program is developed to find the optimal voltage and frequency for linear fitting between the capacitance change and cell concentration. Future work will employ machine learning-based data analysis to drug resistance sensitivity test of cell lines and cell survival status.

Diffusion and Electrophoretic Transport of DNA Polymers in Microfluidic Channels Made of PDMS

2011 ◽  
Vol 312-315 ◽  
pp. 1091-1096 ◽  
Author(s):  
Ronny Sczech ◽  
Steffen Howitz ◽  
Michael Mertig
Keyword(s):  
Single Molecule ◽  
Equilibrium Configuration ◽  
Microfluidic Channels ◽  
Dna Molecules ◽  
Applied Potential ◽  
Electrical Fields ◽  
High Gradients ◽  
Electrophoretic Transport ◽  
Optimized Conditions ◽  
Dna Trapping

DNA molecules can be transported through microchannels with help of electrophoresis and flow. Confinement of DNA molecules leads to elongation of their unconstrained equilibrium configuration when passing the microchannel. Application of electrical fields reduces the mobility and entails DNA trapping because of high gradients of the field due to a decrease in the channels’ magnitude. Microfluidic channels in polydimethylsiloxane (PDMS) were formed by soft replica molding technology combining micro- and nanofluidic features. The applicability of the hybrid micro- and nanofluidic PDMS structures for single molecule observation and manipulation was demonstrated by introducing single molecules of λ-DNA into the channels using optimized conditions for the applied potential and flow.

A two degrees of freedom comb capacitive-type accelerometer with low cross-axis sensitivity

2019 ◽  
Vol 13 (3) ◽  
pp. 5334-5346
Author(s):  
M. N. Nguyen ◽  
L. Q. Nguyen ◽  
H. M. Chu ◽  
H. N. Vu
Keyword(s):  
Degrees Of Freedom ◽  
Proof Mass ◽  
Vibration Modes ◽  
Electrode Structure ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Fully Differential ◽  
Mode Effects ◽  
The Finite Element Analysis ◽  
Cross Axis

In this paper, we report on a SOI-based comb capacitive-type accelerometer that senses acceleration in two lateral directions. The structure of the accelerometer was designed using a proof mass connected by four folded-beam springs, which are compliant to inertial displacement causing by attached acceleration in the two lateral directions. At the same time, the folded-beam springs enabled to suppress cross-talk causing by mechanical coupling from parasitic vibration modes. The differential capacitor sense structure was employed to eliminate common mode effects. The design of gap between comb fingers was also analyzed to find an optimally sensing comb electrode structure. The design of the accelerometer was carried out using the finite element analysis. The fabrication of the device was based on SOI-micromachining. The characteristics of the accelerometer have been investigated by a fully differential capacitive bridge interface using a sub-fF switched-capacitor integrator circuit. The sensitivities of the accelerometer in the two lateral directions were determined to be 6 and 5.5 fF/g, respectively. The cross-axis sensitivities of the accelerometer were less than 5%, which shows that the accelerometer can be used for measuring precisely acceleration in the two lateral directions. The accelerometer operates linearly in the range of investigated acceleration from 0 to 4g. The proposed accelerometer is expected for low-g applications.

Charging Potential Measurement of Floating Electrode Modeled on the Arc Shield of Vacuum Interrupter under AC Voltage Application

2021 ◽  
Vol 141 (1) ◽  
pp. 21-26
Author(s):  
Hideaki Fukuda ◽  
Kenta Yamamura ◽  
Issei Fujita ◽  
Ryutaro Kusa ◽  
Yasushi Yamano
Keyword(s):  
Potential Measurement ◽  
Vacuum Interrupter ◽  
Voltage Application ◽  
Floating Electrode

Effect of Shielding a Floating Electrode on the Power Efficiency of a Micro-plasma VUV Light Source

2015 ◽  
Vol 135 (3) ◽  
pp. 114-115 ◽  
Author(s):  
Ryoto Sato ◽  
Daisuke Yasumatsu ◽  
Shinya Kumagai ◽  
Masaru Hori ◽  
Minoru Sasaki
Keyword(s):  
Light Source ◽  
Power Efficiency ◽  
Floating Electrode
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