Soft Gel-free ECG electrodes based on Biocompatible Coconut-Oil and Carbon Black

Abstract

Recent developments in telemedicine have caused significant interest in the prolonged monitoring of bioelectric signals. This drives the search for easy-to-use, biocompatible, and environmentally friendly alternatives to conventional resistive wet electrodes. Here we demonstrate the use of Coconut-Oil and Carbon Black based stretchable electrodes to monitor electrophysiological signals without the need for conductive gels. The developed material is embedded into an elastomer matrix, exhibits a specific resistance ρ of 33.2 ± 12.3 Ω m, high conformability, and a stretchability up to 1500 %. The realised epidermal electrodes were used to record Electrocardiographic (ECG) signals in a 3-lead configuration and compared to commercial wet electrodes. Even after being elongated by 100 % for 100 stretch/release cycles, a reliable recording of the QRS-complex is demonstrated without the need for any contact enhancing or skin irritating substances, proving its potential use in long term ECG monitoring applications.

Biocompatible Gel-Free Coconut Oil and Carbon Black Electrodes for ECG and Respiration Measurements

“…In this article we propose the use of coconut-oil (CNO) based elastomer composites with a high concentration of Carbon Black (CB) particles to fabricate highly stretchable dry electrodes to perform ECG measurements and respiration detection (Figure 1). As reported in previous works, a soft and highly stretchable biocompatible material with low specific resistance can be fabricated by mixing CNO with CB in an elastomeric matrix [25], [26]. Mixing CB and Ecoflex only by stirring will generate a very low conductive material, therefore a dispersant is required.…”