SU-8/silicon hybrid three dimensional intraneural electrode array

This paper presents the fabrication of a silicon based three dimensional intraneural electrode array. The electrode array consists of a 3 by 4 array of needles with a 250 μm center to center distance and 50 μm separation between neighboring needles. The length of each penetrating portion of the needle is defined by the starting silicon material thickness. We present the fabrication details to build 1 mm tall needles with 250 to 400 μm of their height insulated in SU-8. We are able to present a simpler, more elegant, more reproducible, and more scalable process than the current state of the art method that relies on glass insulation and a dicing saw by using deep reactive ion etching to produce needles and SU-8 to electrically isolate them.