While implantable Neural Interfaces hold great promises for longitudinal neuroscience studies and clinical neural prosthesis, the longevity of functional performance presents a major hurdle for practical applications. In all chases, signal quality decreases over time and ultimately fails. Device failure can occur through multiple different modes including surgery quality, device placement, material failure, gliosis, neural degeneration, metablic injury to neurons, neural circuit disconnect, meningeal regrowth, and device pull-out. Due to the complex and sometime combination of failure modes, the exact mechanisms that lead to implant performance failure and the rate of associated failure remains a mystery. However, intelligent device design of next-generation neural interfaces cannot be pursued without first understanding the intimate details of each failure mode. This project aims to dis-entangle the failure modes through in vivo multiphoton microscope, visually evoked intracortical and subcortical electrophysiology, multichannel immunohistochemistry, and comprehensive electrochemical and material characterization (EIS, CV, SEM, EDX).
Kozai TDY, Catt K, Li X, Gugel ZV, Olafsson VT, Vazquez AL, Cui XT. Mechanical failure modes of chronically implanted planar silicon-based neural probes for laminar recording. Biomaterials. 2015. 37. 25-39.