Opportunities and challenges for flexible and printable electrodes in electroencephalography

The electroencephalogram (EEG) is a commonly used non-invasive approach to monitoring the brain, and has

been used in applications from epilepsy diagnosis to Brain-Computer Interfaces (BCI). The EEG electrode plays a crucial role in the setup of the EEG. While many bulk metal rigid electrodes are available commercially, flexible and stretchable electrodes are needed to improve user comfort, speed of set up, and signal quality. This paper overviews the current state-of-the-art in flexible EEG electrode manufacturing methods, including

3D printing, screen printing, inkjet printing, and other non-printing techniques such as chemical fabrications and classical molding, highlighting the opportunities and challenges present.