Miniaturized Transmission-Line Sensor for Broadband Dielectric Characterization of Biological Liquids and Cell Suspensions

Journal
IEEE transactions on microwave theory and techniques / Symposium issue  
Volume
63
Issue
10
Start Page
3026
End Page
3033
Article Number
7244256
Citation
IEEE Transactions on Microwave Theory and Techniques 10 (63): 7244256 (2015-10-01)
Publisher DOI
10.1109/TMTT.2015.2472009
Scopus ID
2-s2.0-84959548645
The nondestructive characterization of biological liquids and cell suspensions using electromagnetic waves in the microwave frequency range calls for accurate and sensitive measurement devices. Especially when reducing the sample volume, the sensitivity becomes a critical design parameter for broadband sensors. In this paper, a miniaturized transmission-line sensor based on a coplanar waveguide is used to characterize the permittivity of nanoliter volumes of biologically relevant liquids and cell suspensions. The sensor's sensitivity is increased by means of electrically small discontinuities within the sensing section. The biological samples are guided across the sensor in a microfluidic channel, which is fabricated using microsystems technology. The sensor is used between 850 MHz and 40 GHz to detect the broadband permittivity of liquid samples such as aqueous salt and protein solutions. The experimentally detected contrast between living and dead Chinese hamster ovary cells in suspension is significant despite the small sample volume.
Subjects
Biological cells
Chinese hamster ovary cell line (CHO-K1)
mammalian cell culture
microfluidics
microwave measurement
permittivity
transmission-line measurements