Impact of width and spacing of interdigitated electrode on impedance-based living cell monitoring studied by computer simulation

Abstract

The 3D computer simulation based on the finite element method was performed to obtain the impedance in the presence/absence of adherent living cells. The sensitivity of the inter-digitated electrode was investigated by varying the width (W) and spacing (S) for different number of electrode fingers N. It was found that the peak sensitivity corresponding to W/S < 1 and W/S > 1 exhibited higher sensitivity than W/S = 1. However, the sensitivity was relatively large when W/S < 1. Furthermore, the slope of the peak sensitivity curve decreased with the increase in N, emphasizing the fact that it has greater impact on sensitivity than W/S. It is important to note that the peak sensitivity due to smaller electrode width results in higher sensitivity. Hence, the experimentalists are recommended to choose the smaller electrode geometry with smaller electrode width in order to realize better sensitivity in the presence of adherent cell.

An analytical formula for determining the electrical impedance between a single adherent cell and sensor substrate

“…Planar interdigitated electrode arrays are fabricated at low cost, and the theory and simulation methods are well-established. 26,27) Parallel-facing electrodes are used in the flow cytometry for analyzing single cells, 28,29) and this electrode structure has the capability of screening single cells with high throughput. 29) Microelectrode arrays can identify where a target cell exists and map it at moderate resolution.…”