High-response humidity sensing with graphene oxide/lignosulfonate and laser-induced graphene for respiratory health

) at 90% humidity with a sensitivity of 147.73%/% RH. Moreover, the sensor displays an impressively brief recovery period, which remains unaltered even after multiple cycles. Additionally, the humidity sensor exhibits excellent stability for a period of up to 30 days. This study has successfully developed a simple and efficient method for preparing graphene, and has produced a flexible resistive sensor with high sensitivity, repeatability, and stability, thereby opening up new avenues for the high-value utilisation of lignin.