Disclosed is a high impedance system (100) for generating an electric field. The system (100) includes a pair of electrodes (+?a,-?a) comprising a dielectric material (105). The dielectric material (105) has a combination of permittivity, maximum allowable electric field stress and resistivity selected to substantially prevent electrical conduction current through a subject fluid (115). The dielectric coating (105) also generates and directs the electric field through the subject fluid (115) with sufficient intensity and duration to cause electroporation in biological cells suspended in the subject fluid (115). Each electrode (+?a,-?a) has at least one surface coated with an electrically conductive material (110). The dielectric material (105) forms a barrier separating the conductive coating (110) from the subject fluid (115) under treatment. The system (100) also includes a fluid pathway or space area formed between the pair of electrodes (+?a,-?a) such that the conductive material (110) is on an electrode surface not in contact with the subject fluid (115) in the pathway or space. A time variant, time invariant, or pulsed voltage is applied across the electrodes (+?a,-?a) by a voltage source. The system (100) further includes a housing containing the pair of electrodes (+?a,-?a). The housing is configured to maintain a subject static or dynamic fluid in the pathway or space.
