A yarn/fabric-based microfluidic patch for sweat sensing and monitoring

Wearable microfluidic devices have become a popular method in real-time health monitoring, especially for the non-invasive harvest and detection of human sweat, which is closely related to physiological and metabolic status of human body. In this study, a yarn/fabric sweat sensor patch was fabricated based on colorimetric analysis and quantitative analysis of sweat sensing assisted by a smartphone. The microfluidic pattern was composed by the hydrophilic yarn and fabric as the microfluidic channel and reservoir constructed upon the hydrophobic patch. The colorimetric assay of the sensor comprises two aspects, including assessing the content of target analyte through comparison with the reference markers as well as through mobile phone app assistance. The correlation between RGB and content of the biomarkers in human sweat can be established for fast reading of wellness status with high accuracy and effectivity. These sensing patches were deployed on 6 healthy volunteers aged from 20 to 23 to follow the physiological parameter changes during exercise process. After 20 min running, pH, Cl(- )concentration and glucose concentration was recorded respectively as 5.18-6.92, 56.8-70.0 mM, and 44.9-87.6 mu M, which consistent with the normal range of human body. The patch with the yarn/fabric patterned microfluidic analysis system has proposed a simple and feasible approach for non-invasive testing of human wellness assessment, exhibiting great potential in point-of-care diagnosis and healthcare issues.