TY  - CONF
AU  - Dinkić, J.
AU  - Lević, S. M.
AU  - Nedović, Viktor
AU  - Obradović, Nina
AU  - Đorđević, Antonije
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16182
AB  - Suspended viable cells significantly influence the relative complex permittivity (dielectric constant) of the suspension. This influence depends on the concentration, viability, size, and even the cell shape. Hence, by measuring the permittivity, various fermentation processes can be monitored (e.g., in wine making and preparation of milk products). Thereby, the complex impedance (or admittance) between electrodes immersed into the suspension is measured and the permittivity is obtained by a suitable de-embedding procedure.
There exist various data in the literature on this influence, but they do not provide sufficient information for wide implementation of the technique. The aim of the paper was to experimentally investigate various aspects of the measurement procedures and establish practical guidelines and limitations.
Measurements were performed using an LCR meter, a classical vector network analyzer, and a nanoVNA analyzer, in the frequency range from 10 Hz to 100 MHz. Various suspension containers and systems of electrodes were designed and manufactured.
Bipolar systems of electrodes were found to be more suitable for higher frequencies than tetrapolar ones. Open electrode systems were found to be more prone to the influence of the environment than shielded systems (e.g., coaxial).
Good results were obtained for simple yeast suspensions. However, the presence of other cells and dispersed solids (e.g., in pressed grape juice) was found to completely overshadow the yeast cells. Electrochemical effects on the electrodes were found to be insignificant above around 200 kHz. Bubbles on electrodes, delamination, high concentrations of ions, and even temperature variations significantly hindered measurements in many cases.
PB  - Belgrade : University of Belgrade - Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
T1  - Radio-frequency electrical characterization of viable-cell suspensions
SP  - 38
EP  - 38
UR  - https://hdl.handle.net/21.15107/rcub_dais_16182
ER  - 

@conference{
author = "Dinkić, J. and Lević, S. M. and Nedović, Viktor and Obradović, Nina and Đorđević, Antonije",
year = "2023",
abstract = "Suspended viable cells significantly influence the relative complex permittivity (dielectric constant) of the suspension. This influence depends on the concentration, viability, size, and even the cell shape. Hence, by measuring the permittivity, various fermentation processes can be monitored (e.g., in wine making and preparation of milk products). Thereby, the complex impedance (or admittance) between electrodes immersed into the suspension is measured and the permittivity is obtained by a suitable de-embedding procedure.
There exist various data in the literature on this influence, but they do not provide sufficient information for wide implementation of the technique. The aim of the paper was to experimentally investigate various aspects of the measurement procedures and establish practical guidelines and limitations.
Measurements were performed using an LCR meter, a classical vector network analyzer, and a nanoVNA analyzer, in the frequency range from 10 Hz to 100 MHz. Various suspension containers and systems of electrodes were designed and manufactured.
Bipolar systems of electrodes were found to be more suitable for higher frequencies than tetrapolar ones. Open electrode systems were found to be more prone to the influence of the environment than shielded systems (e.g., coaxial).
Good results were obtained for simple yeast suspensions. However, the presence of other cells and dispersed solids (e.g., in pressed grape juice) was found to completely overshadow the yeast cells. Electrochemical effects on the electrodes were found to be insignificant above around 200 kHz. Bubbles on electrodes, delamination, high concentrations of ions, and even temperature variations significantly hindered measurements in many cases.",
publisher = "Belgrade : University of Belgrade - Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia",
title = "Radio-frequency electrical characterization of viable-cell suspensions",
pages = "38-38",
url = "https://hdl.handle.net/21.15107/rcub_dais_16182"
}

Dinkić, J., Lević, S. M., Nedović, V., Obradović, N.,& Đorđević, A.. (2023). Radio-frequency electrical characterization of viable-cell suspensions. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
Belgrade : University of Belgrade - Faculty of Mechanical Engineering., 38-38.
https://hdl.handle.net/21.15107/rcub_dais_16182

Dinkić J, Lević SM, Nedović V, Obradović N, Đorđević A. Radio-frequency electrical characterization of viable-cell suspensions. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia. 2023;:38-38.
https://hdl.handle.net/21.15107/rcub_dais_16182 .

Dinkić, J., Lević, S. M., Nedović, Viktor, Obradović, Nina, Đorđević, Antonije, "Radio-frequency electrical characterization of viable-cell suspensions" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia (2023):38-38,
https://hdl.handle.net/21.15107/rcub_dais_16182 .