Materials approaches for modulating neural tissue responses to implanted microelectrodes through mechanical and biochemical means

• Key aspects of brain tissue response to implanted microelectrodes are introduced.
• Mechanical design factors, including material and form factor, are discussed.
• Biochemical design approaches are reviewed.
• Challenges and future directions for the field are proposed.

Implantable intracortical microelectrodes face an uphill struggle for widespread clinical use. Their potential for treating a wide range of traumatic and degenerative neural disease is hampered by their unreliability in chronic settings. A major factor in this decline in chronic performance is a reactive response of brain tissue, which aims to isolate the implanted device from the rest of the healthy tissue. In this review we present a discussion of materials approaches aimed at modulating the reactive tissue response through mechanical and biochemical means. Benefits and challenges associated with these approaches are analyzed, and the importance of multimodal solutions tested in emerging animal models are presented.