Planar interdigitated array electrodes for RF exposure of biological samples

In this paper, a setup based on a planar electrodes device for applying radiofrequency (RF) signals to biological samples and allowing real-time microscopic observations is presented and further characterized. The device is impedance matched for RF signals at 27 MHz and 1960 MHz using a triple stub tuner resulting in a reflection coefficient lower than -10 dB. The planar electrodes device was modelled and simulated with a 3D numerical method FDTD. The results obtained show a better homogeneity of the SAR distribution, at the electrodes, at 27 MHz compared to 1960 MHz. The whole volume SAR was 3.5 W/kg/1mWinc. This setup will allow, for example, the study of transmembrane potential or calcium signaling in biological cells exposed to RF or pulsed electric fields.