MicroSweat: A Wearable Microfluidic Patch for Noninvasive and Reliable Sweat Collection Enables Human Stress...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Physiology

Background:

• Stress significantly impacts cognitive, behavioral, and physiological health, often leading to chronic illness.
• Current methods for stress detection and measurement are inadequate.
• Cortisol in sweat offers a promising external biomarker for internal stress states, but reliable collection methods are lacking.

Purpose of the Study:

• To develop a reliable, wearable sweat collection device for accurate stress monitoring.
• To validate the use of sweat cortisol as a biomarker for stress levels.
• To establish personalized, longitudinal sweat cortisol profiles from various body locations.

Main Methods:

• Fabrication of a flexible, self-powered, evaporation-free capillary microfluidic device (MicroSweat).
• Collection of human sweat from multiple body locations.
• Detection and quantification of cortisol levels in sweat using the MicroSweat device.
• Correlation analysis between sweat cortisol concentrations and perceived stress levels (Perceived Stress Scale).

Main Results:

• MicroSweat reliably collected sweat and detected cortisol levels indicative of severe stress (25-125 ng/mL across regions, 100-1000 ng/mL from axilla).
• A positive nonlinear correlation was observed between sweat cortisol concentration and perceived stress.
• Longitudinal and personalized sweat cortisol profiles were obtained from various body locations, accounting for individual variations.

Conclusions:

• The MicroSweat device provides a reliable method for collecting sweat and measuring cortisol for stress assessment.
• This technology enables non-invasive, personalized monitoring of stress biomarkers.
• The acquired sweat cortisol data is valuable for personalized and clinical healthcare applications in stress analysis.