title: Microfluidic device for trapping and monitoring three dimensional multicell spheroids using electrical impedance spectroscopy.
abstract: In this paper, we report the design, fabrication, and testing of a lab-on-a-chip based microfluidic device for application of trapping and measuring the dielectric properties of microtumors over time using electrical impedance spectroscopy (EIS). Microelectromechanical system (MEMS) techniques were used to embed opposing electrodes onto the top and bottom surfaces of a microfluidic channel fabricated using Pyrex substrate, chrome gold, SU-8, and polydimethylsiloxane. Differing concentrations of cell culture medium, differing sized polystyrene beads, and MCF-7 microtumor spheroids were used to validate the designs ability to detect background conductivity changes and dielectric particle diameter changes between electrodes. The observed changes in cell medium concentrations demonstrated a linear relation to extracted solution resistance (Rs), while polystyrene beads and multicell spheroids induced changes in magnitude consistent with diameter increase. This design permits optical correlation between electrical measurements and EIS spectra.
authors.affiliation: BioMEMs and Microfabrication system Laboratory, Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33172, USA ; Bioengineering Center, Draper Laboratory, Tampa, Florida 33612, USA ; Electrical Engineering, University of South Florida, Tampa, Florida 33620, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Luongo
authors.affiliation: Bioengineering Center, Draper Laboratory, Tampa, Florida 33612, USA.
authors.forename: Angela
authors.initials: A
authors.lastname: Holton
authors.affiliation: BioMEMs and Microfabrication system Laboratory, Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33172, USA.
authors.forename: Ajeet
authors.initials: A
authors.lastname: Kaushik
authors.affiliation: Bioengineering Center, Draper Laboratory, Tampa, Florida 33612, USA.
authors.forename: Paige
authors.initials: P
authors.lastname: Spence
authors.affiliation: Department of Molecular Medicine, University of South Florida, Tampa, Florida 33620, USA.
authors.forename: Beng
authors.initials: B
authors.lastname: Ng
authors.affiliation: Department of Molecular Medicine, University of South Florida, Tampa, Florida 33620, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Deschenes
authors.affiliation: Bioengineering Center, Draper Laboratory, Tampa, Florida 33612, USA.
authors.forename: Shankar
authors.initials: S
authors.lastname: Sundaram
authors.affiliation: BioMEMs and Microfabrication system Laboratory, Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33172, USA.
authors.forename: Shekhar
authors.initials: S
authors.lastname: Bhansali