A multi-shank silk-backed parylene neural probe for reliable chronic recording

Many chronic brain implants would benefit from a neural probe with many densely configured electrodes with stable recording quality. We present a novel strategy to scale up the number of electrodes with minimized risk of proportionally increasing the adverse foreign body reactions. A flexible parylene probe having 64 electrodes has been designed and fabricated with unique geometries for reduced tissue reactions. Biocompatible silk fibroin was patterned to provide a biodegradable mechanical support of the flexible probe during insertion. We validated the design with in vivo recording in rats and observed no significant deterioration in recording quality for over 5 weeks.