Recent Advances toward Wearable Sweat Monitoring Systems

Wearable biosensors are playing an increasingly important role in society. Compared with traditional wearable biosensors for detecting blood pressure, blood oxygen, or pulse conditions, which can only access information from the physical level, biosensors for testing body fluids can provide more details on health conditions through the analysis of biochemical criteria. Sweat secreted from glands distributed throughout the body contains abundant biochemical information and is an indicator of the physical conditions. Because of the noninvasive and safe sampling method, wearable sweat monitoring systems have the potential to realize long-term and wearable detection. In this review, the current situation of wearable sweat monitoring systems is summarized from three critical parts: the sweat collection method, the sweat analysis method, and the energy supply. Finally, based on the existing drawbacks of wearable sweat monitoring systems in previous studies, the authors creatively propose droplet-based detection, triboelectric nanogenerator-based detection, and self-powered systems as new directions for future research. The proposed approaches are expected to promote the commercialization process of wearable sweat monitoring systems.