Electroporation has been found to be a very effective approach to introduce low and high molecular weight molecules such as drugs, hormones, proteins, DNA, and chromosomes into biological cells. Although electroporation has been under investigation for long time, the dynamic formation and resealing of pores is still not completely understood. In this work, we first computationally analyzed the electric field dosimetry for a Gigahertz Trans­verse Electromagnetic chamber. We found that this exposure method suffered from undesirable field polarity oscillations. Using a novel micro-fabricated microcuvette and pulse delivering system, we conducted a series of experimental studies of electroporation of HL-60 cells. Theoretical models were also employed to describe the mechanisms for pore formation and development of a spherical (HL-60) cell. A locally constrained surface tension model was proposed to represent the cytoskeleton and anchor proteins in the cell membrane and was observed to provide a plausible explanation for experi­mental evidence of long-lived pores. Also, transport mechanisms of small charged molecules associated with electroporation were analyzed.