Innovative Ultra-High-Density Microelectrode Arrays Based on CMOS and MEMS Technology

This study proposed a novel ultra-high-density (supporting up to 65,536 channels) 3D microelectrode arrays (MEAs) based on CMOS devices intended for advanced brain-computer interface (BCI) applications. The proposed MEAs structure combines the advantages of traditional models, like the Utah and Michigan type electrodes, offering the ability to precisely record and generate cortical electroencephalography (EEG) signals in 3D space. Through microelectromechanical systems (MEMS) technology, a compact and highly integrated system was fabricated, which effectively reduced losses and noise interference during signal transmission. The electrode design employed a 32 × 32 microprobe array with 64 electrodes in each microprobe shank, enabling high spatial resolution neural signal recording and stimulation. Results from electrochemical analysis suggested that the electrode had an impedance of approximately 620 kΩ at a frequency of 1 kHz and a charge injection capacity of 0.85 mC/cm², indicating its effectiveness for in vivo neurostimulation applications. This advancement in BCI technology provided significant technical support for scenarios requiring highly precise neural control, such as motor rehabilitation for paralyzed patients.