UC Berkeley

Electroporation - the permeabilization of the cell membrane lipid bilayer due to a pulsed electric field - has important implications in the biotechnology, medicine, and food industries. Although the physical mechanism that causes electroporation is not entirely understood, it is believed that pulsed electric fields significantly increase the potential difference across the cell membrane, resulting in the formation of pores. Depending on the magnitude and duration of a pulsed electric field, membrane permeabilization is either reversible or irreversible. Reversible electroporation is commonly used to transfer macromolecules such as proteins, DNA, or drugs into cells, and the destructive nature of irreversible electroporation makes it suitable for cell ablation and sterilization.

Most electroporation devices have facing electrodes that generate uniform electric fields. Consequently, the magnitudes of these electric fields are inversely proportional to the distance between the electrodes. Since reversible and irreversible electroporation require electric field magnitudes on the order of 1 and 10 kV/cm, respectively, large potential differences are required to induce electroporation. Reducing the potential difference required to perform electroporation eliminates the need for a power supply, making electroporation cheaper and more accessible.

Singularity-induced micro-electroporation - an electroporation configuration composed of two adjacent electrodes separated by a nanoscale insulator - aims to reduce the potential difference required to perform electroporation. Application of a small potential difference between the electrodes creates a radially varying electric field emanating from the insulator. Secondary current distribution models of singularity-induced micro-electroporation show that applying a potential difference as low as 2.9 V creates an electric field that is capable of inducing reversible and irreversible electroporation. To date, the lowest potential difference used to perform irreversible electroporation is ~20 V. More impressively, these models demonstrate that the ohmic drops in galvanic electrochemical cells can generate electroporation-inducing electric fields, enabling the creation of a self-powered micro-electroporation device.