Just now published as a back cover feature article in the journal Lab on a Chip, our paper titled “Soft, Wearable, Microfluidic System for Fluorometric Analysis of Loss of Amino Acids Through Eccrine Sweat.” The system combines our skin-interfaced microfluidic technology with chemical reagents for fluorescence-based readout of the concentrations of targeted amino acids in sweat. Amino acids are essential in support of homeostatic balance and healthy body functions. Eccrine sweat can represent a significant loss channel during exercise. Our devices provide users with an understanding of amino acid turnover and thus feedback on the need for supplement intake – particularly important in competitive sports and for endurance athletes.  This level of function – which notably does not require correlations between sweat and blood chemistry – pairs nicely with our commercial platforms for monitoring sweat and electrolyte loss through @epicorebio in partnership with @Gatorade for sports (the Gx patch) and with various large companies in the oil/gas, the manufacturing and the mining industries for worker safety.  Soft microfluidic technologies and optical readout schemes represent proven, cost-effective, manufacturable platforms for quantitative sweat analytics across many important applications, with near-term additional opportunities in medical care. Thanks to Dr. Seunghee H. Cho and Dr. Soongwon Cho for leadership across all experimental aspects, to Dr. Zhengyao Lv and Prof. Yonggang Huang for contributions in computational fluid dynamics and to Prof. @roozyg for advice on designs for manufacturability. pubs.rsc.org/en/content/arti…