Microfluidic-Integrated Multimodal Wearable Hybrid Patch for Wireless and Continuous Physiological Monitoring

Despite extensive advances in wearable monitoring systems,mostdesigns focus on the detection of physical parameters or metabolitesand do not consider the integration of microfluidic channels, miniaturization,and multimodality. In this study, a combination of multimodal (biochemicaland electrophysiological) biosensing and microfluidic channel-integratedpatch-based wireless systems is designed and fabricated using flexiblematerials for improved wearability, ease of operation, and real-timeand continuous monitoring. The reduced graphene oxide-based microfluidicchannel-integrated glucose biosensor exhibits a good sensitivity of19.97 (44.56 without fluidic channels) & mu;A mM(-1) cm(-2) within physiological levels (10 & mu;M-0.4mM) with good long-term and bending stability. All the sensors inthe patch are initially validated using sauna gown sweat-based on-bodyand real-time tests with five separate individuals who perspired threetimes each. Multimodal glucose and electrocardiogram (ECG) sensing,along with their real-time adjustment based on sweat pH and temperaturefluctuations, optimize sensing accuracy. Laser-burned hierarchicalMXene-polyvinylidene fluoride-based conductive carbon nanofiber-baseddry ECG electrodes exhibit low skin contact impedance (40.5 k & omega;cm(2)) and high-quality electrophysiological signals (signal-to-noiseratios = 23.4-32.8 dB). The developed system is utilized toaccurately and wirelessly monitor the sweat glucose and ECG of a humansubject engaged in physical exercise in real time.