Planar printed electrodes for electroporation with high EM field homogeneity

Abstract

Up to date, several designs of planar electroporation (EP) electrodes have been reported. We propose a novel planar general array-type electrode design, which can be optimized for a desired area of exposure, electric field magnitude and high field homogeneity (uniformity). Unlike other designs that mostly use interdigitated electrodes with alternating potentials, in this design the same polarity electric potentials are used on all elements of the electrode array, with a circular ground electrode surrounding the electrode array. Thereby, an exposure area can be increased and the electric field depth is increased, as well. We describe the procedures used for the design optimization, applicable in general to this type of arrays. Following the initial theoretical assessment, we use full-wave numerical simulations for the design optimization. The electric field measurements on printed circuit board prototypes are included to validate the numerical calculations. Two designs (type A/type B) are presented. Field homogeneity with less than 10% variation in the majority of points of interest is observed, for the designed area of exposure sufficient to place a standard Petri dish bottom (35 mm diameter), and field levels comparable with those obtained in cuvettes. We perform EP experiments in order to confirm the expected EP efficiency. Results confirm high EP efficiency as well as possible easy adaptation of this electrode type for various design specifications. The proposed electrode design is low-cost, scalable, it allows flexible adjustment of the exposure area by adding additional array elements, and both in vivo and in vitro utilization is envisioned with somewhat different applicator mountings.