Skin Conformal Polymer Electrodes for Clinical ECG and EEG Recordings

TLDR

Preparation‑free, skin‑compliant biopotential electrodes with high recording quality enable future wearable healthcare and the Internet of Humans. The study presents super‑soft, self‑adhesive electrodes for use on dry and hairy skin without skin preparation or attachment pressure. The electrodes feature microstructured, grasshopper‑foot‑inspired surfaces that adhere repeatedly with up to 0.1 N cm⁻² force, and soft macropillars enable alpha‑wave detection through dense hair. The electrodes achieve 50 kΩ cm² impedance at 10 Hz, reduce noise and motion artifacts to gel‑electrode levels, record high‑fidelity ECGs in water, detect EEG alpha through hair, are nearly imperceptible, cause no skin irritation, and enable unobtrusive long‑term clinical‑grade recordings.

Abstract

Abstract Preparation‐free and skin compliant biopotential electrodes with high recording quality enable wearables for future healthcare and the Internet of Humans. Here, super‐soft and self‐adhesive electrodes are presented for use on dry and hairy skin without skin preparation or attachment pressure. The electrodes show a skin‐contact impedance of 50 kΩ cm 2 at 10 Hz that is comparable to clinical standard gel electrodes and lower than existing dry electrodes. Microstructured electrodes inspired by grasshopper feet adhere repeatedly to the skin with a force of up to 0.1 N cm −2 without further attachment even during strong movement or deformation of the skin. Skin compliance and adhesive properties of the electrodes result in reduction of noise and motion artifacts superior to other dry electrodes reaching the performance of commercial gel electrodes. The signal quality is demonstrated by recording a high‐fidelity electrocardiograms of a swimmer in water. Furthermore, an electrode with soft macropillars is used to detect alpha activity in the electroencephalograms from the back of the head through dense hair. Compared to gel electrodes, the soft biopotential electrodes are nearly imperceptible to the wearer and cause no skin irritations even after hours of application. The electrodes presented here could combine unobtrusive and long‐term biopotential recordings with clinical‐grade signal performance.