Encapsulation Materials for Neural Interface Devices: Investigation of A-sicx:h and Parylene-c Thin Films As Encapsulation Materials for Neural Interface Devices

Neural interface devices have been developed for neuroscience and neuroprosthetics applications to record and stimulate nerve signals. Chronic use of these devices is prevented by their lack of long- term stability, due to device failure or immune system responses. Conformal, hermetic, biocompatible, and electrically insulating coating materials that sustain chronic implantation and guarantee stable recording or stimulation are needed. Even though a large selection of materials has been proposed and tested for this purpose, to date, no material presented in scientific literature has been thoroughly characterized and qualified as a long- term hermetic encapsulation material for silicon- based neural interface devices. In this work, hydrogenated amorphous silicon carbide (a-SiCx: H) and Parylene-C films were investigated as the encapsulation materials. The deposition parameters and corresponding film properties were explored and correlated with the encapsulation characteristics.