Fully Printed Wearable Microfluidic Devices for High-Throughput Sweat Sampling and Multiplexed Electrochemical
Rajendran Vinoth1,2, Tatsuo Nakagawa3, Jayaraman Mathiyarasu1,2
1Electrodics and Electrocatalysis Division, CSIR-Central Electrochemical Research Institute (CECRI), Karaikudi 630003, Tamil Nadu, India.
ACS Sensors
|February 1, 2021
Summary
This study presents a novel, low-cost wearable biosensor for real-time sweat analysis during exercise. The device enables multiplexed electrochemical monitoring of key biomarkers, enhancing personalized health and athletic performance tracking.
Area of Science:
- Biomedical Engineering
- Analytical Chemistry
- Materials Science
Background:
- Wearable biosensors offer continuous, noninvasive sweat analysis but face challenges in multiplexing, rapid sampling, and interference-free data collection.
- Existing systems struggle with integrating microfluidics and portable electronics for practical, real-time monitoring of physiological markers.
Purpose of the Study:
- To develop a clean-room-free fabricated wearable microfluidic sensor for electrochemical monitoring of sweat biomarkers during exercise.
- To enhance sweat sampling and transport properties for rapid, multiplexed analysis.
- To integrate the sensor with a portable potentiostat for interference-free data collection and wireless signal transduction.
Main Methods:
- Utilized screen-printed carbon master for clean-room-free fabrication of wearable microfluidic sensors.
- Incorporated low-dimensional sensing compartments and silane functionalization to improve sweat sampling and reduce hydrophilicity.
- Developed a miniature circuit board for simultaneous amperometric lactate and potentiometric ion (Na+, K+, pH) sensing with cross-talk-free signal collection.
- Mounted the integrated, pumpless microfluidic device on the epidermis for real-time sweat analysis during stationary biking.
Main Results:
- Achieved rapid (within 40 s) real-time sweat transport through the microfluidic channel to active sensing electrodes.
- Demonstrated simultaneous sensing of lactate, Na+, K+, and pH with high sensitivity, selectivity, stability, and repeatability.
- Verified that floating potentiometric circuits effectively eliminate signal interference from adjacent amperometric transducers.
- Successfully analyzed regional variations in sweat composition by comparing underarm and upper back measurements during exercise.
Conclusions:
- The developed wearable microfluidic sensor enables large-scale, inexpensive, high-throughput fabrication for personalized point-of-care and athletic applications.
- The clean-room-free approach and integrated design overcome previous bottlenecks in wearable sweat biosensing.
- This technology facilitates multiplexed, real-time decoding of sweat biomarkers, offering valuable insights into physiological status during physical activity.
