What are common moisture/dry skin issues that affect electrode adhesion and how should they be handled?

• A. Sweaty or oily skin reduces adhesion; dry with a towel, use conductive gel or hydrogel, and ensure skin is clean and dry before applying electrodes
• B. Dry with a towel, use conductive gel or hydrogel, and ensure skin is clean and dry before applying electrodes
• C. Use no gel and force adhesion
• D. Skin condition has no effect

Answer: (A)

Adhesion of surface electrodes depends on a clean, dry, and stable skin-electrode interface. Moisture from sweat or skin oils creates a slick surface and increases interfacial impedance, making it harder for the electrode to stick and for current to flow evenly. Dry skin can also hinder contact if oils are not removed or if the surface is rough. The way to handle this is to prepare the skin properly: wipe away sweat and oils with a towel or pad, and ensure the area is clean and completely dry before placing electrodes. If the skin is dry or the contact is inconsistent, applying a thin layer of conductive gel or hydrogel can improve both adhesion and conductivity, helping the electrode stay in place and maintain a stable impedance.