Multifunctional Graphene Sensor Ensemble as a Smart Biomonitoring Fashion Accessory

Biomonitoring wearable sensors based on two-dimensional nanomaterials have recently elicited keen research interest and potential for a new range of flexible nanoelectronic devices. Practical nanomaterial-based devices suited for real-world service, which exhibit first-rate performance while being an attractive accessory, are still distant. We report a multifunctional flexible wearable sensor fabricated using an ultrathin percolative layer of graphene nanosheets on laser-patterned gold circular interdigitated electrodes for monitoring vital human physiological parameters. This graphene on laser-patterned electrode (GLE) sensor displays an excellent strain resolution of 245 με (0.024%) and a record high gauge factor of 6.3 × 10⁷, with exceptional stability and repeatability in its operating range. The sensor was tested for human physiological monitoring like measurement of heart rate, breathing rate, body temperature, and hydration level, which are vital health parameters, especially considering the current pandemic scenario. The sensor also served in applications such as a pedometer, limb movement tracker, and control switch for human interaction. The innovative laser-etch process used to pattern gold thin-film electrodes, with the multifunctional incognizable graphene layer, provides a technique for integrating multiple sensors in a wearable band. The reported work marks a giant leap from the conventional banal devices to a highly marketable multifunctional sensor array as a biomonitoring fashion accessory.