PEDOT:PSS-treated laser-induced graphene-based smart textile dry electrodes for long-term ECG monitoring

Abstract

Reliable detection of physiological signals from the human body is essential for health monitoring, preventive care, and treatment. Wearable bioelectronics that are directly placed on the epidermis surface represent a promising future biopotential sensing option. Wearable textile electrodes for biopotential sensing are a promising candidate for long-term health monitoring. Smart textiles, which incorporate electronic functionality into a fabric, enable the seamless integration of sensors for a variety of purposes into garments. This paper describes the direct writing of laser-induced graphene (LIG) on a Kevlar textile for the production of a reusable poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS)-coated LIG Kevlar textile and its application as a reusable dry electrode for electrocardiography (ECG). The transformation of Kevlar into graphene is caused by the photothermal effect induced by laser irradiation. This structure allows functions to be incorporated into the textile while maintaining its flexibility and comfortability for wear. As prepared, these electrodes possess excellent electrical conducting behaviour and demonstrate a skin–electrode contact impedance of 100 ± 3 kΩ to 7.9 ± 3 kΩ for frequencies ranging from 40 Hz to 1 kHz, nearly 13% lower than most conventional wet electrodes made of Ag/AgCl. The proposed dry electrode produces an ECG signal comparable to clinical devices with conventional wet electrodes. Even after several hours of use, these electrodes cause no skin irritation and work effectively without needing skin preparation. Due to its simplicity and low cost, the proposed PEDOT:PSS-treated LIG Kevlar textile electrode is suitable for practical applications.