Stability of Softening Neural Interfaces With a-SIC Thin Film Interlayer
Neural interfaces are implantable devices that enable communication between a computer and nervous tissue to read, write and block neural activity within targeted nerves. To improve the chronic use of neural interfaces, the materials used to develop them have been evolving with time, leading to softer and thinner layers of the involved materials to minimize the foreign body response from the body caused by the implanted device. Recently, researchers have studied many biocompatible polymers that promise to extend the lifetime of neural interfaces. An emerging materials class of interest, softening polymers (SPs), has performance advantages (while stiff and rigid) similar to Parylene-C and Polyimide during fabrication, handling, and insertion, but after softening (e.g. once implanted into the body), this class of polymers demonstrates enhanced conformability. This dissertation work (1) describes the flexibility and performance as an insulator of thiol-ene based softening polymers, (2) details a fabrication process of SP-based devices integrating amorphous silicon carbide (a-SiC) as an encapsulation layer and (3) elucidates structure-property-processing relationships of a-SiC SP neural interfaces via long-term electrical stability after accelerated aging and cyclic bending for future use in chronic animal studies.