Monitoring of yeast cell concentration using a micromachined impedance sensor

E.E. Krommenhoek, Johannes G.E. Gardeniers, Johan G. Bomer, Albert van den Berg, X. Li, M. Ottens, L.A.M. van der Wielen, G.W.K. van Dedem, M. van Leeuwen, W.M. van Gulik, J.J. Heijnen

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The paper describes the design, modelling and experimental characterization of a micromachined impedance sensor for on-line monitoring of the viable yeast cell concentration (biomass) in a miniaturized cell assay. Measurements in a Saccharomyces cerevisiae cell culture show that the permittivity of the cell suspension depends linearly on the biomass concentration within the range of 0 to 9 g/l. In order to compensate the measurements for changes in the dielectric properties of the background electrolyte, the use of a three-electrode configuration in combination with a semi-permeable pHEMA membrane was explored. Measurements showed that the impedance of the hydrated pHEMA varies with only the background electrolyte conductivity, and not with the concentration of cells, indicating that pHEMA is suitable for this purpose. The optimal pHEMA membrane thickness was determined using finite element modelling.
Original languageUndefined
Title of host publicationThe 13th International Conference on Solid-StateSensors, Actuators and Microsystems, (Transducers 2005)
Place of PublicationUSA
Number of pages4
ISBN (Print)0-7803-8994-8
Publication statusPublished - 5 Jun 2005
Event13th International Conferences on Solid-State Sensors, Actuators and Mircosystems, TRANSDUCERS 2005 - Seoul, Korea, Republic of
Duration: 5 Jun 20059 Jun 2005
Conference number: 13

Publication series



Conference13th International Conferences on Solid-State Sensors, Actuators and Mircosystems, TRANSDUCERS 2005
Abbreviated titleTRANSDUCERS
Country/TerritoryKorea, Republic of


  • METIS-223988
  • Dielectric spectroscopy
  • IR-51047
  • Microporous membrane
  • cell concentration
  • permittivity
  • pHEMA
  • EWI-18737

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