Wearable Sensors for Tracking Health and Physiological Status from Human Sweat

Central Electro Chemical Research Institute (CSIR-CECRI), Karaikudi, has developed a low-cost wearable sensor for tracking the health and physiological status of the human body by monitoring dynamic levels of biomarkers from sweat. The sensor can avoid the necessity for invasive tests. The microfluidic sensor can continuously monitor multiple analytes simultaneously and is completely free from sensor-to sensor signal transfer problems.

Wearable sensors are ideal non-invasive platforms for continuously monitoring biologically relevant biomarkers from human body fluids. Sweat consists of vital biochemical information that could potentially indicate the health and physiological status of the human body. The in-situ sweat sampling and continuous analysis of key biomarkers can avoid repetitive, painful blood sampling processes. Developing microfluidic sensors with rapid sweat sampling and multiplexed electrochemical recognition abilities is extremely important for accurate sweat biomarker analyses.

The Institute has developed a low-cost flexible microfluidic patch using a screen-printing technique that does not depend on expensive clean-room facilities. The flexible sensor can be simply worn on any irregular body surface like underarm or upperback locations. The sensor can non-invasively measure different biomarkers present in sweat such as lactate, Na+, K+, and its pH simultaneously. 

The sensor has a fluidic channel that captures real-time sweat and flows through the active sensing areas of the sensor via capillary force of attraction without the help of any external pump. A miniaturized printed circuit board was developed for wirelessly collecting sensor signals directly to the mobile or laptop. The microfluidic patch is attached to the skin and used for in-situ monitoring of sweat compositions during stationary biking. The patch tracks the hydration level and oxygenation of muscles which is essential for fitness monitoring application. The patch can further be modified for monitoring other disease indicators like glucose, cortisol, etc. 

This research was published in the journal ACS Sensor.

The Institute is further working to make the sensor stretchable as well so that it can maintain its performance even under mechanical deformation. The stretchable sensors can avoid cracking or device damage during irregular body motion or muscle movements. Additionally, Dr Vinu Mohan and his team are exploring other reliable biofluids such as saliva and interstitial fluid as they contain abundant chemical markers that could reflect the underlying physiology of the human body. These wearable biosensors are important for clinical diagnosis and personalised point-of-care analysis.



Dr Vinu Mohan A.M., 
Electronics and Electrocatalysis Division, 
CSIR-Central Electrochemical Research Institute (CECRI), 
Karaikudi, Tamil Nadu