Graphene oxide-based radiofrequency identification wearable sensor for breath monitoring

The monitoring of the breathing dynamic characteristics, including the presence of biomarkers in exhaled breath, is of growing interest in non-invasive diagnosis of diseases. The authors describe a wearable radiofrequency identification device hosting a flexible antenna suitable for integration into a facemask and a sensor made of graphene oxide sensitive to the humidity variations. The resulting sensor tag was characterised in reference conditions while its communication performance was estimated by electromagnetic simulations as well as measurements over a simplified model of the human head. Finally, the whole system was tested on a volunteer and was experimentally demonstrated to be capable of detecting the inhalation/ exhalation cycles and abnormal patterns of respiration like the apnea by measuring the changes in graphene oxide resistance.