Biosensors: Perspiration is a Good Thing

Those of us who live in warm climates understand how important it is to stay hydrated, especially in a place like Phoenix, Arizona.  We emphasize this starting with youth sports.  We remind visitors who want to enjoy hiking our beautiful state the importance of staying hydrated.  But many people are not aware about how quickly they can become dehydrated and find themselves in distress.

Staying hydrated has been a top concern in sports for many years.  During the recent National Basketball Association finals, Miami Heat star, Lebron James, was unable to finish one game due to severe leg cramps.  The FIFA World Cup is being held in Brazil under extreme heat and humid conditions.  In a rare move, FIFA is allowing water breaks during the game.  The time is added on as stoppage time.

A water break during the FIFA World Cup was used during the USA v Portugal match.  This Sunday during the Netherlands v Mexico match the referee called for a water break during both halves.  However, the water breaks were left to the discretion of the referee.  He bases his decision on the air temperature, relative humidity and his own subjective observation of the players. 

Perspiration sensing and sweat analysis is gaining more attention.  Tracking this data is important for elite athletes but also the general public.  There are medical conditions and illnesses that benefit from sweat analysis for diagnosis and treatment.  Some of these conditions are cystic fibrosis and stress levels in autistic children.

There are some wearable consumer devices that have perspiration detection.  The Basis smartwatch uses a galvanic response sensor to measure skin moisture to help determine workout intensity.  The Jawbone Bodymedia armband has a skin conductance sensor.  One of the many rumors swirling around a potential Apple iWatch is that it will have a sweat sensor, among other sensors.  But as someone who lives in a dry climate, like Arizona, I will tell you that perspiration evaporates quickly.  I need to know my hydration level and electrolytes.

There is ongoing research to deliver wearable sensors that can better determine hydration levels, and other biomarkers.  There are several research institutes and universities around the world working in this area.  Sweat analysis is done at the clinical level, but delivering this in a wearable and easy to use product is the challenge.  Real time sweat analysis using wearable micro-fluidic devices is an area of research.

MC10, a startup in Cambridge, MA is working closely with top athletes to deliver a biostamp.  This is a flexible circuit that can be worn like a BandAid.  It is worn like a second skin and records biometric data: heart rate, hydration levels, muscle activity and sleep patterns.  It has an integrated smartphone application.  MC10 has nine athletes on its Sports Advisory Board.  The company plans to make the biostamp available commercially in 2015.  The applications go beyond sports to medical and defense.

Electrozyme in La Jolla, CA is another startup working on what it calls Temporary Tattoo Biosensors.  The sensors are screen printed using proprietary ink blends.  The platform technology was originally developed at the University of California San Diego’s Laboratory for Nanoelectronics.  The tattoo biosensor is used to analyze the chemical constituents of sweat.

During this recent FIFA World Cup, data is given on how much players have run on the field.  They wear activity trackers to deliver this data.  It will not be long before biosensors that determine hydration levels, and other factors will be worn routinely by athletes.  Whether or not how much of this personal data will be shown is a matter for the various sports organizations to determine.  The high profile of these biosensors will likely spur adoption into consumer products such as wearables and clothing.  Higher end solutions will be developed for medical and military applications.  There will be more sensors that will gather more data about us to promote health and fitness.