2024 AIChE Annual Meeting
Development of a Wearable Fabric Sensor for Noninvasive Lactate Monitoring during Exercise
This work focuses on the development of a wearable fabric sensor using novel nanocomposite materials. Currently, there is no established method for noninvasive and continuous monitoring of lactate levels during exercise. This sensor will facilitate the gathering and analysis of sweat biomarkers, specifically lactate, furnishing insights into human health and performance monitoring. Lactate was selected as the analyte of interest to measure the exertion of the participant, and the material to be developed will provide real-time health assessment and performance optimization. Excess lactate build-up has been implicated in causing cramping, fatigue, and diminished performance in athletes. To fabricate such a sensor, an electrospun nylon fabric is treated via vacuum filtration with a solution. The solution utilizes carboxylic acid functionalized multi-walled carbon nanotubes (MWCNTs) that are dispersed in water with a surfactant using a probe sonicator. These lactate sensing materials were characterized via SEM and FTIR to determine the morphology of the nanocomposite sensor material. The sensor's active layer is then synthesized by electropolymerization using pyrrole, lactate oxidase, and a second aqueous dispersion of carboxylic acid functionalized MWCNTs. Characterization of MWCNT dispersion quality and particle size were completed through UV-vis spectroscopy and Zetasizer analysis. Electrochemical properties were evaluated through cyclic voltammetry of the sensor's response to synthetic sweat solutions containing lactate. Further testing involved analyzing sensor responses to spiked and synthetic sweat solutions containing common biomarkers within sweat such as glucose, potassium, calcium, and sodium. Initial benchtop tests have confirmed the sensor's ability to detect physiologically relevant levels of sweat lactate. The nanocomposite sensors are to be validated thoroughly via an IRB-approved on-body lab testing, which will provide feedback to the design to be used for further development. Participants will cycle for 60 minutes and sweat samples will be collected with sterile gauze adhered to the skin using Tegaderm. We aim to test 30 subjects for validation of the wearable fabric sensor. After testing, the gauze is centrifuged and analyzed for the lactate concentration using the gold standard laboratory technique, HPLC.