DOI: https://doi.org/10.29363/nanoge.cybioel.2024.050
Publication date: 28th June 2024
Recording and stimulation using implantable neural implants has been demonstrated as an effective diagnosis and treatment for neurological disorders (i.e. Parkinson’s disease, epilepsy) as well as in neuroprosthesis applications. [1] Conventional devices are fabricated using rigid materials such as metal or silicon which has a significantly higher young’s modulus compared to the neural tissue leading to foreign body reaction (in chronic implantations) due to the mechanical mismatch. [2] Current research in the field is focusing on developing soft and flexible electrodes to better mimic and conform the natural tissue property and reduce the risk of implant rejection. [3] On the other hand, surgical implantation of ultra-soft electrodes to the target location in the brain in a minimally invasive manner remains a challenge. In addition, it is crucial to achieve minimum stab damage during insertion. Therefore, in this project, the goal is to fabricate shuttles using femtosecond laser ablation to facilitate the insertion of ultra-soft neural electrodes at the target site and achieve minimally invasive insertion as well as minimum stab damage to the neural tissue without buckling of the shuttle. Simulations of buckling force is used to optimise the geometry, size and material of the shuttle whereas the laser parameters are optimised for different materials (i.e. tungsten, stainless steel, silicon) to achieve a sharp shuttle tip. The insertion force required to penetrate neural tissue has been previously reported as a relevant metric to assess the extent of caused tissue damage. [4] Here we therefore optimize shuttle geometry, material, and fabrication process to minimize insertion force, which is measured using a motorised micromanipulator on a brain phantom at different insertion speeds. The fabricated shuttles will then be used for the implantation of ultra-soft electrodes.