| dc.description.abstract | The brain is one of the most complex systems in the human body. During the past century, efforts have been made the development of tools that allow us to explore the functionality and structure of the brain. Up to now, only a few neural devices have been able to demonstrate significant clinical impacts, such as deep brain stimulation, visual prostheses for the restoration of useful vision, spinal cord implants for the restoration of locomotion in cases with spinal cord injury, and cochlear implants. As long-term monitoring of the brain still remains challenging, much effort has been devoted in the last years to develop compliant implants with mechanical properties similar to the brain that conform along with the tissue and generate a small implantation footprint.
Neuronal tissues are very soft, and implanting rigid neural probes causes scars, and due to their micromovements, the scars become worse. The immune system tries to fix the damage by creating an encapsulation layer around the probe. Therefore, in the long term, the probe loses its functionality by not being able to interface with surrounding neurons. This thesis focuses on improving neural probes to reduce implantation trauma. Two approaches have been followed during this work. First, utilizing soft material to reduce the mechanical mismatch between implant and tissue. Therefore, the probe complies with the stiffness of the tissue and does not hurt the tissue very deeply. Second, reducing the cross-sectional footprint of the probe. Therefore during surgical implantation, the trauma will be reduced. In this regard, the thesis includes a theoretical review, COMSOL Multiphysics simulation for buckling analysis, microfabrication in the cleanroom, and mechanical and electrical characterization in the lab followed by insertion tests in a brain model (phantom) that simulates brain tissue. | |