The temporal electric field strength in skin during a plasma jet treatment: a new door for electroporation

Electroporation has been widely used for cancer treatment, drug delivery, and so on. When a plasma is applied topically on a human being, it might also induce electroporation effect on the skin. However, such electric field strength in the skin induced by plasma has never been measured. In this paper, a helium plasma jet driven by a pulsed direct current (DC) power supply is in contact with a skin which is placed on a Bi₄Ge₃O₁₂ (BGO) crystal. The time-resolved electric field strength in the skin including in the stratum corneum (SC) and in the viable epidermis and dermis layer is measured by Pockels effect. It is found that the maximum electric field strength in the SC reaches 43 kV/cm while the electric field in the viable epidermis and dermis layer reaches about 1.8 kV/cm. Such electric field strength is within the typical required strength of electroporation but it does not induce any painful sensation, which is the unavoidable side effect of the traditional electroporation. Thus, this “plasmaporation” might open a new door for electroporation.