Abstract— An electrode is a conductive material that, on one side, is connected to a metallic component (such as a copper wire) and, on the other side, to a non-metallic component (such as a semiconductor, electrolyte, or vacuum) within an electrical circuit, establishing a connection between them. Biological electrodes provide a link between the human body and an electrical circuit, ultimately enabling the circuit to transmit useful data to a computer for analysis in various applications. Various types of electrodes are used for recording bio-potentials, which, based on the type of contact, can be classified into two categories: (1) wet electrodes and (2) dry electrodes. Wet electrodes require the application of conductive materials, such as conductive gel, before attachment to ensure optimal contact. However, these materials can cause inconveniences for both the patient and the operator, such as the need to prepare the skin (e.g., shaving) or to clean the site after signal acquisition. Consequently, dry electrodes have become increasingly popular due to their ease of use for both patients and operators. Nonetheless, one challenge of this type of electrode is the high electrical contact impedance caused by the absence of conductive substances. In this study, a low-cost dry electrode based on a silver-powder sintering process on a copper substrate was designed to enhance EEG signal quality and signal-to-noise ratio (SNR) without requiring conductive gels.
