An Efficient, Large-Gradient, Electrical Stimulation System to Promote Directional Neural Growth

There is significant interest in developing electric field (EF) application into a technology that will direct nerve regeneration and potentially therapeutics that can restore nervous system function. In fact, EFs are naturally generated in the body and have been shown to be an essential catalyst for promoting the healing of skin wounds. In the case of skin injuries, selective localization of ionic pumps has been shown to generate an electric potential across the skin epithelium. Injury to the skin shorts this potential, leading to the generation of an electric gradient along the axis of the wound, with the negative potential localized to the centre of the wound [1] . Skin epithelial cells have been shown to be sensitive to this electric gradient, directing their migration along the gradient towards the centre of the lesion. Eventually, skin epithelial cells seal the wound, causing the electrical gradient to collapse. Similarly, a large body of research has shown that nerve axons are electro-sensitive and grow towards the more negative potential in the presence of an EF [2] . Exploiting this biological phenomenon for clinical application requires approaches that can generate large gradients along the tissue to support growth and regeneration.