Description
Demand for limb reanimation has prompted the development of neural probe technology. Neural probes have an array of electrodes that stimulate neurons, in order to reactivate previously defunct electrical pathways in the brain. The ultimate objective of restoring these neural connections is to reinstitute normal body functions and capabilities. This study will explore the possibility of improving electrocorticography (ECoG) neural probes through examination of geometry on impedance, employing a mechanical approach on glassy carbon and metal adhesion interface for interface optimization, and develop 3-dimensional glassy carbon electrodes to improve the neural probe quality and electrode impedance. In this study photolithographic mask design is altered to include an array of electrodes with various diameters, to assess how the order of magnitude changes for impedance. Addtionally the GC/metal interface is evaluated through a mechanical approach by changing the amount of surface area contact for metal bonding. The opening for metal to contact electrode is called the vias and this allows for a metal connection between the electrodes and bump pads. Designs with smaller vias are called MeDroC, and those with larger vias are called MeGloC. Although MeDroc and MeGloc vary in the amount of surface area for metal and electrode contact, both design contain the fundamental array composition of different sized electrodes. These glassy carbon electrodes are created through pyrolysis of SU8, with the microelectrode arrays fabricated using the aforementioned photolithographic masks to pattern and design the entire device. During each step, the devices are optically imaged using Hirox Digital Microscope and Scanning Electron Microscope (SEM) and then tested through electrochemistry to find its impedance at 1 kHz frequency.
