Description
Research into neural prostheses has shown the immense potential of such devices as well as their current limitations. This is especially true in regards to 3-D electrode arrays and the current materials used in their production. This study demonstrates the tuneability of polymeric pyrolyzed carbon in regards to its mechanical and electrical characteristics for the purpose of exploring it's viability as a candidate for current neural prostheses. The pyrolyzed carbon is achieved from a negative tone photoresist which allows for a great deal of freedom in terms of design and fabrication as conventional lithographic techniques and processes can be employed. In this study, carbon pillars were designed and fabricated from the negative tone photoresist precursor SU-8. The pillars were rendered conductive via UV Light exposure, to induce crosslinking, followed by pyrolyzation which is the method by which the "tuning" occurs. By varying the parameters of pyrolyzation, pillars of varying electrical conductivity, stiffness, and electrochemical reactivity were obtained. Pillars were created at pyrolyzation temperatures of 600, 700, 800, 900, and 1000°C. The electrical properties of the pillars were analyzed via Electrochemical Impedance Spectroscopy (EIS), so as to observe the behavior of the electrodes in a wet ionic environment. The mechanical properties of Glassy carbon were explored individually, through use of an SDSU developed nanoindentation system, and as part of a complete hybrid glassy carbon/metal device. The Hybrid devices were explored further via EDX and an Instron universile testing machine.
