In 1924, almost 100 years ago, Hans Berger discovered that brain electrical activity can be non-invasively recorded from the human head by placing sensors on the scalp. Today, multi-channel electroencephalography (EEG) acquisition is well established in neuroscience research and clinical applications, typically requiring an elastic cap or net to hold the sensors in place. In addition, a conductive paste or gel is necessary to ensure a low impedance bridge between the electrode surface and skin. However, this technology has several drawbacks. For example:

• Cap preparation is time consuming.
• Electrode caps worn for long periods of time may cause discomfort or headaches.
• Hair washing is required after taking off the cap.
• Traditional caps are obvious and therefore distracting in real-life settings. 

Aiming towards unobtrusive EEG acquisition, we have developed the cEEGrid technology. cEEGrids are flex-printed, multi-channel sensor arrays that are placed around the ear using an adhesive. cEEGrids are lightweight, comfortable to wear and discreet; some users have even reported to forget they are wearing them during activities of daily life. Importantly cEEGrids are not dry, requiring a tiny amount of gel, thereby combining the advantages of wet EEG sensor technology with the benefits of dry sensor solutions, while avoiding both of their drawbacks. This website demonstrates how to prepare the cEEGrids on a person, how to obtain EEG data with them and, most interestingly, which brain signals can be recorded with cEEGrids.