Model of an Interdigitated Microsensor to Detect and Quantify Cells Flowing in a Test Chamber

E. Bianchi[1], F. Boschetti[1], G. Dubini[1], and C. Guiducci[2]
[1]Politecnico di Milano, LABS, Laboratory of Biological Structure Mechanics, Structural Engineering Department, MI, Italy
[2]CLSE - Swiss Up Chair -Laboratory of Life Science Electronics, EPFL, Losanna, Swissland
Published in 2010

Microfabricated planar interdigitated electrodes can detect and analyze cells or particles giving an impedance-based characterization. This method presents several advantages: real-time detection, label-free analysis, non-invasive sensing, easiness of integration and high-throughput screening. A numerical model of an interdigitated planar micro sensor was realized in order to optimize and pre-validate the design of micro-fabricated gold micro-sensor. The electrochemical impedance spectroscopy sensor was designed to quantify the cells, flowing in a parallel flow chamber in a HBSS solution and adhering to a specifically coated surface, where the electrodes are located. Two interdigitated electrodes lay on a pyrex substrate. 2D and 3D time-harmonic analyses were carried out by COMSOL Multiphysics to evaluate the sensitivity of the sensor to the presence of cells on and among the electrode branches: impedance was considered as function of input voltage frequence. Several interdigitated micro sensor configurations were compared in order to draw out reliable design guidelines and to better interpret future experimental data.

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