ED dipole string electrical impedance measurements at B12

1979 ◽  
Author(s):  
R. Shafer
Keyword(s):  
Electrical Impedance ◽  
Impedance Measurements

scholarly journals Dry Film Resist Laminated Microfluidic System for Electrical Impedance Measurements

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 632
Author(s):  
Yuan Cao ◽  
Julia Floehr ◽  
Sven Ingebrandt ◽  
Uwe Schnakenberg
Keyword(s):  
Microfluidic Chip ◽  
Electrical Impedance ◽  
Microfluidic System ◽  
Equivalent Circuits ◽  
Proof Of Concept ◽  
Impedance Measurements ◽  
Close Match ◽  
Aspect Ratios ◽  
Lamination Process ◽  
Dry Film

In micro-electrical-mechanical systems (MEMS), thick structures with high aspect ratios are often required. Dry film photoresist (DFR) in various thicknesses can be easily laminated and patterned using standard UV lithography. Here, we present a three-level DFR lamination process of SUEX for a microfluidic chip with embedded, vertically arranged microelectrodes for electrical impedance measurements. To trap and fix the object under test to the electrodes, an aperture is formed in the center of the ring-shaped electrodes in combination with a microfluidic suction channel underneath. In a proof-of-concept, the setup is characterized by electrical impedance measurements with polystyrene and ZrO2 spheres. The electrical impedance is most sensitive at approximately 2 kHz, and its magnitudes reveal around 200% higher values when a sphere is trapped. The magnitude values depend on the sizes of the spheres. Electrical equivalent circuits are applied to simulate the experimental results with a close match.

Electrical impedance measurements for pulmonary disease diagnosis

1992 ◽  
Vol 13 (A) ◽  
pp. 171-174 ◽  
Author(s):  
J N Sahalos ◽  
E Vlachogiannis ◽  
C Koukourlis ◽  
G Kyriacou ◽  
K Batas
Keyword(s):  
Pulmonary Disease ◽  
Electrical Impedance ◽  
Disease Diagnosis ◽  
Impedance Measurements

scholarly journals Low Cost Instrumentation for Electrical Impedance Tomography in Biomedical Applications

2015 ◽  
Author(s):  
Stewart Smith ◽  
Hancong Wu ◽  
Jiabin Jia
Keyword(s):  
Electrical Impedance Tomography ◽  
Integrated Circuit ◽  
Biomedical Applications ◽  
Electrical Impedance ◽  
Low Cost ◽  
Impedance Measurement ◽  
Impedance Tomography ◽  
Impedance Measurements ◽  
Additional Circuitry ◽  
Initial Results

This poster reports the design, implementation and testing of a portable and inexpensive bio-impedance measurement system intended for electrical impedance tomography (EIT) in cell cultures. The system is based on the AD5933 impedance analyser integrated circuit with additional circuitry to enable four-terminal measurement. Initial results of impedance measurements are reported along with an EIT image reconstructed using the open source EIDORS package.

Prediction of Frost Hardiness in Douglas Fir Seedlings by Measuring Electrical Impedance in Stems at Different Frequencies

1973 ◽  
Vol 3 (2) ◽  
pp. 256-264 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Survival Data ◽  
Electrical Impedance ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Impedance Measurements ◽  
Temperature Regimes ◽  
Before And After ◽  
Post Test ◽  
Different Levels ◽  
Short Days

Frost hardiness of Douglas fir (Pseudotsugamenziesii Mirb. Franco.) plants was assessed by a range of freezing tests in three experiments. In experiments 1 and 2 plants were grown in different temperature regimes, under short days, for 8 weeks to induce different levels of frost hardiness. In experiment 3, plants remained in the open and were sampled on 21 occasions through one year.Comparison of stem impedance measurements made at 1 kHz, 4.5 kHz, and 1 MHz, before and after freezing tests in experiments 1 and 2, indicated survival of individual plants was well predicted by post test measurements. The postfreezing test 1 kHz/1 MHz ratio distinguished between dead and surviving plants with the smallest number of measurements. Both this ratio and 4.5 kHz impedance provided similar conclusions about treatment effects, which agreed satisfactorily with conclusions from survival data. Impedance ratios of 1 kHz/1 MHz measured in stems after freezing tests accurately predicted survival in experiment 3. Seasonal changes in ratio, determined after freezing to a particular temperature, paralleled seasonal change in plant frost hardiness and was significantly correlated with exposure to cold during 14 days prior to measurement.

Electrical Impedance Measurements of PZT Nanofiber Sensors

2016 ◽  
Author(s):  
Richard Galos ◽  
Xin Li
Keyword(s):  
Dielectric Constant ◽  
Material Properties ◽  
Electrical Impedance ◽  
Impedance Measurement ◽  
Low Frequencies ◽  
Impedance Measurements ◽  
Conductive Afm ◽  
Electrical Impedance Measurement ◽  
Microfabrication Techniques

Electrical Impedance Measurement of PZT Nanofiber sensors are performed and material properties including resistivity and dielectric constant are derived from the measurements. Nanofibers formed by electro-spinning with diameters ranging from 10 to 150 nm were collected and integrated into sensors using microfabrication techniques. The nanosensor impedance was extremely high at low frequencies and special matching circuitry was fabricated to detect output. The resulting impedance measurements are also compared with those of individual nanofibers that were tested using Scanning Conductive Microscopy (SCM) and Conductive AFM.

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