1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Two-dimensional dielectric spectroscopy: Implementation and validation of a scanning open-ended coaxial probe
Rent:
Rent this article for
USD
10.1063/1.3462974
/content/aip/journal/rsi/81/7/10.1063/1.3462974
http://aip.metastore.ingenta.com/content/aip/journal/rsi/81/7/10.1063/1.3462974

Figures

Image of FIG. 1.
FIG. 1.

(a) Schematic graphs of the array configuration for three different electrodes. (a) The selected electrode (◼) is connected to impedance analyzer for the measurement while the rest of electrodes (◻) are connected to the virtual ground. (b) The configuration is analogous to a scanning coaxial probe.

Image of FIG. 2.
FIG. 2.

Equivalent circuit model of monolithic CMOS. See Table I for the practical values of the components.

Image of FIG. 3.
FIG. 3.

Block diagram of array architecture. See the text for a description of the significance of the symbols.

Image of FIG. 4.
FIG. 4.

Impedance measurement system. (a) Complete system. (b) Close-up view of array.

Image of FIG. 5.
FIG. 5.

(a) Equivalent electrical circuit describing a biological sample, represented by a parallel combination of capacitance and conductance , are connected in series with the electrode polarization impedance (a constant phase angle). The effect of total stray capacitance, PCB traces, and interfacing cable inductance are considered as and . Three calibration processes were employed to correct for the anomalies. (b) Equivalent (measured) electrical circuit of the sample.

Image of FIG. 6.
FIG. 6.

Electrode array design.

Image of FIG. 7.
FIG. 7.

Frequency dependence of relative permittivity and conductivity of NaCl solution at two different concentrations 10 mM (○) and 25 mM (◻). Solid lines (–) are best-fit theoretical simulations using the method described in Ref. 14.

Image of FIG. 8.
FIG. 8.

Relative change in the permittivity and conductivity of 20 mM KCl solution as a function of sample thickness. The effective penetration depth is identified as the sample thickness at which the measured dielectric properties deviated from the values for the solution by 1%. Experimental value for was obtained 3.5 mm.

Image of FIG. 9.
FIG. 9.

Relative change in permittivity and conductivity of 20 mM KCl solution as a function of distance between a metal rod and electrode (relative to the values measured in the absence of the metal rod) in two different cases: (a) the object is connected to the system ground and (b) the object is in floating condition.

Image of FIG. 10.
FIG. 10.

Typical permittivity and conductivity spectra for yeast cells suspensions (○) and for the 20 mM KCl solution (◻) used to suspend the cells. Solid lines (–) are best-fit theoretical simulations using the equations described in Secs. II C and ???. Best-fit parameters for the KCl solution were: , , , ; For the cell suspension, the best fit parameters were: , , , , , , , and . The fitting residual, according to Eq. (6), was obtained: 7.2. Morphological parameters: , , , , and . The parameters which were fixed in the data fitting: , , , , and .

Image of FIG. 11.
FIG. 11.

Three-shell model of a cell. is the complex permittivity and is defined as , where is dielectric constant and is the conductivity. In this equation, is the angular frequency of applied field. The indexes m, om, cp, w, and e correspond to the plasma membrane, organelle membrane, cytoplasm, wall, and external medium.

Image of FIG. 12.
FIG. 12.

Frequency dependence of (a) relative permittivity and (b) conductivity of tissue phantom for three different locations of the cell suspension inclusion: inclusion on top of measuring electrode (△), on the top of a neighbor electrode (◻), and far from measuring electrode (○).

Image of FIG. 13.
FIG. 13.

(a) A photograph of the phantom made by gel-containing salt (agar soaked in 20 mM KCl solution) and yeast cell. The samples (yeast cells suspended in KCl solution) were on the top of two selected electrodes. A 2D-map of the distribution of the (b) relative permittivity at 10.5 MHz and (c) conductivity at 120 KHz.

Tables

Generic image for table
Table I.

Electrical specification of three different analog switches.

Generic image for table
Table II.

A comparison of the membrane capacitance and cytoplasm conductivity obtained from this study to published reports.

Loading

Article metrics loading...

/content/aip/journal/rsi/81/7/10.1063/1.3462974
2010-07-23
2014-04-17
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Two-dimensional dielectric spectroscopy: Implementation and validation of a scanning open-ended coaxial probe
http://aip.metastore.ingenta.com/content/aip/journal/rsi/81/7/10.1063/1.3462974
10.1063/1.3462974
SEARCH_EXPAND_ITEM