Abstract
Soft material alginate electrodes may be a potential alternative to platinum electrodes that are used for neural stimulation. The mechanical structure of platinum is rigid and opposes the soft, lumpy tissue environment in which it gets implanted. This puts platinum at a disadvantage for surface interaction and conformity and can even cause damage to brain tissue. Hydrogel electrodes have robust flexibility which may be an advantage for improved interface with nerve tissue and pathways and limit injury. Any device which becomes implanted into the body must meet many safety requirements such as tests of biocompatibility. Primarily, a technique for sterilization of the hydrogel was established by using a chemical method, which involved soaking in ethanol. Once sterilized, the electrode material was cultured with mammalian cells to study cell viability in vitro. Cell metabolic activity in the test condition was comparable to those in normal conditions, suggesting that the material composition had no negative effect on viability and proliferation. The body is a complex system with many cells. To predict other cell responses the material may trigger, an inflammation test was performed in vitro by studying macrophage response with the electrode. This will be done to understand a potential immune response by monitoring whether macrophage population becomes pro-inflammatory, or anti-inflammatory based on phenotype of the cells.