Laser-Induced Graphene Coated Wearable Smart Textile Electrodes for Biopotentials Signal Monitoring

This work describes how to produce a functional nanomaterial using laser induced graphene (LIG) and use it for biomedical applications. Laser induced graphene was manufactured using the low-cost single-step process, laser ablation of polyimide, a commercial polymer. The formation of LIG on PI sheet and other carbonaceous materials has been widely explored meanwhile the characteristics of laser induced graphene has been less explored in its ability to form a stable dispersion. In this work, the characterizations of the LIG in forming a stable dispersion in low boiling solvent was investigated which is both nontoxic and environmentally friendly. The conductivity of the dispersion obtained was better then reduced graphene oxide and comparable to the graphene. The synthesised LIG was used to form a conductive smart textile for the monitoring of biopotentials like electrocardiogram and electromyogram. After successive coating of the graphene dispersion on the cotton fabric to make it conductive, the sheet resistance of the resulting fabric dropped to 3% of its initial value. The laser-induced graphene (LIG) cotton dry electrodes thus manufactured are comparable to Ag/AgCl wet electrodes in terms of the skin-to-electrode impedance, measuring between 78.0 and 7.2 kΩ for the frequency between 40 Hz and 1 kHz. The LIG cotton electrode displayed a signal-to-noise ratio of 20.17 dB. Due to its comfort, simplicity, and good performance over a longer period of time, the textile electrode coated with the functional material appears suited for medical applications.