Multifrequency impedance measurement technique for wireless characterization of microbiological cell cultures

Abstract

An impedance measurement system with probe signal frequencies up to 50 kHz with AC-probe voltages below 30 mV rms was integrated for wireless and battery-free monitoring of microbiological cell cultures. The here presented modular design and the use of state-of-the-art components greatly eases adoptions to a wide range of biotechnological applications without the need of bulky LCR-meters or potentiostats. The device had a power consumption of less than 2.5 mA at a 3.3 V single power supply and worked trouble-free within the humid environment of a cell culture incubator. Measurements on lumped RC-elements showed an error of less than 1% for absolute values and less than 1° regarding the phase of the complex impedance. The performance of sensor devices with interdigitated electrode structures for the measurement of adherent cell cultures was tested in the presence of phosphate-buffered saline solution in the humid atmosphere of an incubator for biological cell cultures.

Inductance analyzer based on auto-balanced circuit for precision measurement of fluxgate impedance

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Towards Recycled Paper Based Impedance Biosensor with Wireless Readout

“…Up to six testing carriers are set on a standard well titer plate equipped with NFC tags, which are wirelessly connected to an electronic readout system sending the measurement values to the computer for data processing (see Figure 2). Wireless electronic readout system carrying a standard 6 well titer plate equipped with 6 NFC tags [3] to perform the impedance measurement of the sensors.…”