Polyethylene Glycol-Coated Polyimide-Based Probe with Neural Recording IC for Chronic Neural Recording

Neural probe array is utilized in neural recording, in the aim to understand the neural activity. Silicon is the common substrate used in neural probe array. However, due to the rigid nature, the silicon-based neural probe array causes cell damage during implantation into the brain tissue. This would reduce the signal-to-noise ratio. Therefore, flexible polymer probe is more suitable as it can help to minimize the tissue damage and thus increasing the signal-to-noise ratio. The lack of stiffness for the flexible probe is solved by coating it with polyethylene glycol (PEG). It stiffens the probe and can be dissolved in water, which allows the polymer probe to regain its flexibility. The proposed integrated probe with reduced distance between probe and ASIC will further help to improve the signal-to-noise ratio during neural recording. The coated flexible probe regained original impedance of 14.1 kΩ at a frequency of 1 kHz. A bench-top neural recording with the flexible probe array in saline solution will also be acquired.