Wei Gao – Nature

We can learn a lot from our sweat. This is an ideal way to have non-invasive wearable sensors on our skin rather than pricking ourselves for blood snapshots. Sweat monitoring provides a way to gather continuous real-time data.

Daniel Rose University of Cincinnati / Photo: Dottie Stover/University of Cincinnati

What we could be monitoring in our sweat:

• glucose (blood sugar)
• lactate (muscle fatigue)
• sodium (hydration)
• potassium (hydration)
• chlorine
• pH
• skin temp (necessary to calibrate the other sensors)

This would be particularly useful for athletes monitoring electrolyte loss and the effects of different supplements. Cystic fibrosis is already diagnosed today using sodium and chloride in sweat. With upwards of 60% of the US population being pre-diabetic or diabetic monitoring glucose and correcting insulin levels is highly desirable today. The applications are wide.

How do we monitor sweat? Well that becomes a involved process.  There are several universities solving those problems and they are publishing the details. I particularly like the Nature paper line of “The more glucose or lactate in your sweat, the more electrical current is generated at the sensor’s surface. And the more sodium and potassium, the larger the voltage.” This offers up an option for the DIYer. We know how to monitor voltage and current.

Sources:

• http://spectrum.ieee.org/biomedical/diagnostics/sweat-sensors-will-change-how-wearables-track-your-health
• https://med.stanford.edu/news/all-news/2016/01/wearable-device-detects-real-time-changes-in-composition-of-sweat.html
• http://www.popsci.com/this-wearable-patch-uses-sweet-to-monitor-blood-glucose-levels
• http://www.ece.uc.edu/devices/publications/Publications/AdhesiveRFID_Rose
• http://www.nature.com/news/wearable-sweat-sensor-paves-way-for-real-time-analysis-of-body-chemistry-1.19254