Hydrogels for emerging wearable sweat monitoring devices

As a vital biofluid, sweat is widely recognized as an ideal diagnostic medium for health monitoring because of its non-invasive sampling and easy accessibility. Hydrogels have emerged as promising materials for wearable sweat-sensing devices owing to their exceptional hydrophilicity, biocompatibility, and tuneable properties, demonstrating significant potential across sweat collection, component analysis, and energy supply for sensing systems. In this paper, the literature on the application of hydrogels in wearable sweat sensing devices is synthesized. The aim of this paper is to summarize and analyse technological innovations and development trends in this field. In terms of the material selection, fabrication strategies, and detection mechanisms of hydrogel-based sweat sensing devices, the functional roles of hydrogels across various stages of sweat detection are detailed. Furthermore, the challenges and future prospects for hydrogel-based sweat sensing are addressed as part of an advanced approach to non-invasive health care.