Fabric-Based Wearable Dry Electrodes for Body Surface Biopotential Recording

Abstract

A flexible and conformable dry electrode design on nonwoven fabrics is examined as a sensing platform for biopotential measurements. Due to limitations of commercial wet electrodes (e.g., shelf life, skin irritation), dry electrodes are investigated as the potential candidates for long-term monitoring of ECG signals. Multilayered dry electrodes are fabricated by screen printing of Ag/AgCl conductive inks on flexible nonwoven fabrics. This study focuses on the investigation of skin-electrode interface, form factor design, electrode body placement of printed dry electrodes for a wearable sensing platform. ECG signals obtained with dry and wet electrodes are comparatively studied as a function of body posture and movement. Experimental results show that skin-electrode impedance is influenced by printed electrode area, skin-electrode interface material, and applied pressure. The printed electrode yields comparable ECG signals to wet electrodes, and the QRS peak amplitude of ECG signal is dependent on printed electrode area and electrode on body spacing. Overall, fabric-based printed dry electrodes present an inexpensive health monitoring platform solution for mobile wearable electronics applications by fulfilling user comfort and wearability.

Kirigami‐Inspired Textile Electronics: K.I.T.E.

“…Printing technology and its associated methods show promise as a postprocessing approach to compensate for the limitations in the integration of conductive fibers and yarns. By printing with conductive inks, researchers have developed functional materials for flexible electronics such as strain sensors, wearable antennas, electrocardiogram sensors, electromyography sensors, and energy harvesting devices . However, all these techniques utilize rigid conductive materials whose mechanical properties vastly differ from the integrated soft textile platform.…”

Review on Smart Electro-Clothing Systems (SeCSs)

“…Screen printing of conductive ink directly on substrates like, film, textile, and nonwoven materials is used as a simple and common technique to develop sensors and electrodes for measuring the electrical signal from the skin surface. Increasing the surface area of the electrode can potentially decrease the skin to electrode impedance and provide a reasonable signal with a comparable signal-to-noise-ratio (SNR) to commercial wet electrodes [22]. Ag/AgCl ink is dominantly used for screen printing dry electrode to enhance the ionic conductivity and lower the skin to electrode impedance, although this requires the generation of sweat on the skin.…”

Flexible Sensors—From Materials to Applications

“…Therefore one of the most important parameters for electropotential sensors is contact resistance. Flexible resistive coupled electrodes were fabricated using Ag/AgCl conductive inks [542,543], Au [539,544,545], graphene [357], CNTs [540,546], AgNPs [546], and PEDOT:PSS [340,355,356,547]. Dry electrodes based on PDMS had a contact impedance of <4 kΩ and remained stable for 5 h [548].…”