A review of electrodes for the electrical brain signal recording

Brain is complex organ composed of numerous glial cells and neurons to convey information using chemical and electrical signals. Neural interface technology using the electrical brain signals has attracted great attention for the clinical and experimental applications. Electrode as the neural interface is the most important part in stimulating neural cells or recording neural activities. In this paper, we provide an overview of electrodes for recording the electrical brain signal. The noninvasive electrodes are primarily used to capture electroencephalogram (EEG) from outside the skull while the implantable electrodes are employed to measure electrocorticogram (ECoG), local field potential (LFP) or spike activity. Recent progress in microfabrication technology enables the development of on-board electrode that combines the entire signal processing including amplification, filtering, and digitization. This will contribute to diagnostic and therapeutic application of the neural interface for restoring physical, psychological and social functions by improving motor, sensory or cognitive abilities.