Advanced materials for neural surface electrodes

• Brain surface electrodes are an optimal tradeoff between invasiveness and signal quality.
• Brain surface electrodes have numerous materials considerations.
• Materials determine both the device function and the brains reactive response.
• Materials science advances continue to yield new materials well-suited for neural applications.
• This review outlines new materials advances for neural electrode arrays.

Designing electrodes for neural interfacing applications requires deep consideration of a multitude of materials factors. These factors include, but are not limited to, the stiffness, biocompatibility, biostability, dielectric, and conductivity properties of the materials involved. The combination of materials properties chosen not only determines the ability of the device to perform its intended function, but also the extent to which the body reacts to the presence of the device after implantation. Advances in the field of materials science continue to yield new and improved materials with properties well-suited for neural applications. Although many of these materials have been well-established for non-biological applications, their use in medical devices is still relatively novel. The intention of this review is to outline new material advances for neural electrode arrays, in particular those that interface with the surface of the nervous tissue, as well as to propose future directions for neural surface electrode development.