Design Fabrication And Characterization Of Microelectrodes For Brain Machine Interfaces

ABSTRACT: The long-term goal in the design of brain-machine interfaces (BMIs) is to restore communication and control of prosthetic devices to individuals with loss of motor function due to spinal cord injuries, amyotrophic lateral sclerosis, or muscular dystrophy, for example. One of the great challenges in this effort is to develop implantable systems that are capable of processing the activity of large ensembles of cortical neurons. This work presents the design, fabrication, characterization, and in vivo testing of a neural recording platform for a pre-clinical application. The recording platform is a flexible, polyimide-based microelectrode array that can be hybrid-packaged with custom electronics in a fully-implantable form factor. Results from the microelectrode array integrated with an amplifier integrated circuit include data from in vivo neural recordings showing consistent single-unit discrimination over 42 days. Moreover, results from the electrochemical assessment of the corrosion properties of the tungsten microwire electrodes used on the microelectrode array admonish the use of tungsten in long-term implants.