Medical Engineering Thesis Defense, Yiran (Isabella) Yang

Location: BBB B180 and, https://caltech.zoom.us/j/84288140866?pwd=NjNLNTBoWFFEYVFaanJRK21hRFFPZz09 Meeting ID: 842 8814 0866 Passcode: hotsweat

Abstract: Wearable sensors have shown great potential in health diagnostics and monitoring. Continuous monitoring of metabolites in sweat could potentially offer great insight into a person's health, but current sweat-sensing technology faces challenges in different realms: The sensing strategies are limited and there is a need to achieve high sensitivity for low-concentration targets and to widen the detection spectrum of chemical targets. The lack of efficient sweat sampling creates inaccurate sensing results from sweat mixing with skin contaminants or sensing byproducts. Moreover, the lack of evaluation of sweat metabolites with respect to relevant clinical conditions and the lack of scalable fabrication techniques pose hurdles in the eventual applications of non-invasive sweat monitoring. In this thesis, efforts advancing progress on these fronts are presented. We demonstrate how to utilize laser-engraving techniques to achieve high-performance graphene sensors for electroactive metabolite sensing and vital signs detection. Then we present our subsequent efforts built on laser-engraved graphene sensors to improve sensing selectivity and widen the detection spectrum to detect non-electroactive targets in sweat. Furthermore, the design and performance of our laser-engraved microfluidics are described and shown to improve sweat sampling in both exercise-induced and iontophoresis-induced sweating individuals. Lastly, we present our endeavors in evaluating sweat biomarkers with clinical conditions in pilot studies involving individuals with gout and metabolic syndrome. In total, the works summarized here could potentially facilitate future applications in precision nutrition.