ULTRA-FLEXIBLE, HIGH-DENSITY NEURAL ELECTRODE PROBES FOR RELIABLE MULTI-REGION NEURAL ACTIVITY MONITORING

We designed, and fabricated an ultra-flexible nanofabricated neural probe to achieve reliable multi-region neural activities recording simultaneously in both superficial and deep structures of brain for freely moving mice. High spiking yield of up to 85.2 % has been achieved for over 8 weeks with a minimally invasive (with each shank only 0.5 mm diameter hole drill for craniotomy) in-vivo implantation. Each probe has 128 recording sites evenly distributed over 4 shanks with each shank length of 2700 microns, cross section of 72 x 1.5 -mu m. The flexible nanofabricated neural probes were then implanted in freely moving mice, achieving both acute and chronic recordings from the neurons in the superficial region motor cortex (M1) and deep region caudate putamen (CPu). The scalable neural probe fabrication methods and high performance ultraflexible probes pave the way towards the brain-wide neural activities monitoring for freely behaving lives.