fig4

Figure 4. (A) Schematic layout of the wearable colorimetric sensing patch and depiction of sweat flow directionality and relative flow rates within the patch. Reproduced with permission^[87]. Copyright 2024, Wiley-VCH; (B) Schematic illustration of the microfluidic sensor and nutrient patch in an exploded configuration: the microchamber architecture for colorimetric analysis, the handheld device photograph, and the optical image of the assembled system situated next to a vitamin tablet. Reproduced with permission^[89]. Copyright 2024, Wiley; (C) Exploded view of a skin-interfacing microfluidic system for personalized sweat-rate and sweat-chloride analysis: patterned microfluidic layer and embedded sensing layer. Reproduced with permission^[76]. Copyright 2020, Science; (D) Overall workflow of the deep-learning-assisted programmable chromatic chip for evaluating sweat glucose, pH, and lactate, including an intelligent imaging device and interpretable convolutional neural network. Reproduced with permission^[86]. Copyright 2022, American Chemical Society.