Capacitance change estimation for an immunosensor chip

This paper presents a low power capacitance to voltage converter (CVC) circuit using two differential amplifier circuits, two Schottky rectifier diodes constructed in symmetrical manner and combined with instrumentation amplifier circuits. The differential capacitance to voltage simulation work has been realized with cheap discrete components. Combination energy from solar, vibration and heat is expected to be used to source the capacitance circuit. Constant dc voltage of 3 V has been used to source the CVC circuit in this work. It is found by the simulation, the converter circuit consumes 3.9 mW of total power, operates at 40 kHz using 400 mV excitation signal. The circuit is able to detect changes of capacitance from 4 â€“ 12.5 pF using reference capacitance of 5 pF. Sensitivity of 0.132 mV for 1 fF capacitance change has been observed in the circuit. This circuit is suitable for wireless health monitoring system.

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Antidiuretic hormone-dependent membrane capacitance and water permeability in the toad urinary bladder

AJP Renal Physiology ◽

10.1152/ajprenal.1983.244.2.f195 ◽

1983 ◽

Vol 244 (2) ◽

pp. F195-F204

Author(s):

L. G. Palmer ◽

M. Lorenzen

Keyword(s):

Antidiuretic Hormone ◽

Water Flow ◽

Time Course ◽

Apical Membrane ◽

Constant Current ◽

Apical Plasma Membrane ◽

Voltage Response ◽

Toad Urinary Bladder ◽

Osmotic Gradient ◽

Capacitance Change

Antidiuretic hormone (ADH) increased the electrical capacitance of apical membrane of the toad bladder; this effect was modulated by the osmotic gradient across the tissue. Capacitance was measured from the transepithelial voltage response to constant-current pulses using bladders depolarized with KCl-sucrose serosal solution to reduce basolateral resistance and with Na-free mucosal solution to increase apical membrane resistance. Addition of ADH (20 mU/ml) increased capacitance by 28 +/- 9% (mean +/- SD) in the absence and by 8 +/- 3% in the presence of an osmotic gradient (200 mosM, mucosal side hypotonic). With bladders stimulated in the absence of an osmotic gradient, rapidly imposing a gradient resulted in a peak rate of water flow that declined to 40% of the peak value after 15-20 min. ADH-dependent capacitance also decreased with a similar time course. Removal of ADH reversed the capacitance change (t1/2 = 10-15 min), but the reversal was slower than the decline in water flow to basal levels (t1/2 less than 5 min). Colchicine and cytochalasin B also inhibited the ADH-induced capacitance increase. The capacitance change was also inhibited when the mucosal solution was made hypertonic with raffinose. The results are interpreted within the framework of a previously proposed model of ADH-stimulated water transport in which cytoplasmic vesicular structures fuse with the apical plasma membrane.

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Dual-Level Capacitive Micromachined Uncooled Thermal Detector

Sensors ◽

10.3390/s19245434 ◽

2019 ◽

Vol 19 (24) ◽

pp. 5434 ◽

Cited By ~ 1

Author(s):

Hani H. Tawfik ◽

Karim Allidina ◽

Frederic Nabki ◽

Mourad N. El-Gamal

Keyword(s):

Integrated Circuits ◽

Performance Comparison ◽

The Other ◽

Effective Length ◽

Capacitance Change ◽

Thermal Detector ◽

Trade Off ◽

Single Level ◽

Level Design ◽

Structural Layer

This paper presents a novel dual-level capacitive microcantilever-based thermal detector that is implemented in the commercial surface micromachined PolyMUMPs technology. The proposed design is implemented side-by-side with four different single-level designs to enable a design-to-design performance comparison. The dual-level design exhibits a rate of capacitance change per degree Celsius that is over three times higher than that of the single-level designs and has a base capacitance that is more than twice as large. These improvements are achieved because the dual-level architecture allows a 100% electrode-to-detector area, while single-level designs are shown to suffer from an inherent trade-off between sensitivity and base capacitance. In single-level designs, either the number of the bimorph beams or the capacitance electrode can be increased for a given sensor area. The former is needed for a longer effective length of the bimorph for higher thermomechanical sensitivity (i.e., larger tilting angels per degree Celsius), while the latter is desired to relax the read-out integrated-circuits requirements. This thermomechanical response-to-initial capacitance trade-off is mitigated by the dual-level design, which dedicates one structural layer to serve as the upper electrode of the detector, while the other layer contains as many bimorph beams as desired, independently of the former’s area.

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Smart Cure Monitoring Method of Carbon/Epoxy Laminates Using Electric Capacitance Change with Applied Alternating Current Frequency

Key Engineering Materials - Advances in Fracture and Strength ◽

10.4028/0-87849-978-4.2903 ◽

2005 ◽

pp. 2903-2908

Author(s):

Takaomi Inada ◽

Akira Todoroki

Keyword(s):

Alternating Current ◽

Capacitance Change ◽

Monitoring Method ◽

Current Frequency ◽

Cure Monitoring ◽

Electric Capacitance

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Micropatterned Pyramidal Ionic Gels Capacitance Change Pressure Sensors

ECS Meeting Abstracts ◽

10.1149/ma2018-01/44/2562 ◽

2018 ◽

Keyword(s):

Pressure Sensors ◽

Capacitance Change

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Highly transparent and flexible graphitic C3N4 nanowire/PVA/PEDOT:PSS supercapacitors for transparent electronic devices

Functional Materials Letters ◽

10.1142/s1793604720510066 ◽

2020 ◽

Vol 13 (02) ◽

pp. 2051006

Author(s):

Jialun Li ◽

Xueyu Zhang ◽

Xuesong Li ◽

Lianfeng Duan ◽

Xijia Yang ◽

...

Keyword(s):

Solid State ◽

Motion Detection ◽

Power Supply ◽

Electronic Devices ◽

Transparent Film ◽

Capacitance Change ◽

Vacuum Filtration ◽

Integrated Electronics ◽

Wearable Electronic ◽

Wearable Electronic Devices

To achieve reliable flexibility and acceptable transparency for integrated electronics, the power supply sources of these devices have to meet the requirement of flexibility and transparency. Herein, we developed a facile and non-toxic way to manufacture all-solid-state supercapacitors with high capacitive performance, transparency and flexibility. The as-prepared g-C3N4 nanowires are distributed in Polyvinyl Alcohol (PVA) and Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) solution, transparent film could be formed by vacuum filtration. The g-C3N4 nanowires provide pseudocapacitance and PVA and PEDOT:PSS matrix provides bendable and stretchable ability. The g-C3N4/PVA electrode achieves a specific areal capacitance of 3.51[Formula: see text]mF[Formula: see text]cm[Formula: see text] with transparency of 85%, and that of g-C3N4/PVA/PEDOT:PSS is 5.32[Formula: see text]mF[Formula: see text]cm[Formula: see text] with transparency of 72%. The facile process provides a reasonable architecture for the preparation of a variety of flexible, transparent and wearable electronic devices. The flexible and transparent devices show an instant response to the finger bending with the capacitance change of more than 25%, which provides the possibility for fabricating smart flexible device to monitor human health and motion detection.

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Wireless strain monitoring using electrical capacitance change of tire: part I—with oscillating circuit

Smart Materials and Structures ◽

10.1088/0964-1726/12/3/311 ◽

2003 ◽

Vol 12 (3) ◽

pp. 403-409 ◽

Cited By ~ 25

Author(s):

Akira Todoroki ◽

Shintaro Miyatani ◽

Yoshinobu Shimamura

Keyword(s):

Electrical Capacitance ◽

Capacitance Change ◽

Strain Monitoring

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Flow control with active dimples

The Aeronautical Journal ◽

10.1017/s0001924000004887 ◽

2007 ◽

Vol 111 (1125) ◽

pp. 705-714 ◽

Cited By ~ 19

Author(s):

S. Dearing ◽

S. Lambert ◽

J. Morrison

Keyword(s):

Pressure Sensors ◽

Fast Response ◽

Vortex Generators ◽

Control Surface ◽

Real Time Control ◽

Capacitance Change ◽

Time Control ◽

Design And Manufacture ◽

Smart Skin

Abstract The long-term goal is to design and manufacture optimal ‘on-demand’ vortex generators, ‘dimples’ that can produce vortices of prescribed strength and duration for the real-time control of aerodynamic flows that are either undergoing transition or are fully turbulent, attached or separating. Electro-active polymers (EAP) are ideal for a dimple control surface, offering high strain rate, fast response, and high electromechanical efficiency. EAP can also be used as the basis of a resistanc – or capacitance – change pressure sensor, development of which has just begun. In terms of manufacture, inkjet printing of EAP also offers a paradigm shift such that a monolithic control surface is a very real possibility. Important features for integration into a control system are robustness and a predictable, repeatable motion. With these objectives in mind, the suitability of EAP-based actuators is assessed both mechanically and aerodynamically. The ultimate goal is to integrate these devices, along with shear-stress and pressure sensors and distributed control, also under development, into a flexible ‘smart skin’ which could be incorporated into an airframe structure. The response of a laminar boundary layer to forcing is investiagted using mechanical dimples.

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Stresses in Films Deposited by Planar Magnetron Sputtering on Glass Substrates of Different Thickness

MRS Proceedings ◽

10.1557/proc-130-383 ◽

1988 ◽

Vol 130 ◽

Author(s):

Zhi-Feng Zhou ◽

Yu-Dian Fan

Keyword(s):

Magnetron Sputtering ◽

Magnetic Characteristics ◽

Substrate Thickness ◽

Back Side ◽

Structure And Properties ◽

Capacitance Change ◽

Glass Substrates ◽

Thin Film Thermocouple ◽

Planar Magnetron ◽

Different Thickness

AbstractStresses affect the structure and properties of the films significantly. In this paper, Co-Cr films were deposited by D.C. planar magnetron sputtering on rectangular glass plates of thickness varied from 0.18 to 2.00mam. The measurement of stress was performed by the bending plate technique with the detection of capacitance change. The temperature of the bending plate was measured by an Fe-Ni thin film thermocouple on the back side of the substrate. The experimental results showed that the stresses were all tensile, but in the films on the thicker substrates were smaller than that on the thinner ones. And apparently the temperature rise of the thicker substrates during deposition was lower than that of the thinner ones. The magnetic characteristics of the Co-Cr films related to the substrate thickness may be attributed to both stress and temperature difference in the films deposited on the substrates of different thickness.

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