Bio-inspired hierarchical wearable patch for fast sweat collection.

Area of Science:

• Biomedical Engineering
• Materials Science
• Wearable Technology

Background:

• Wearable sweat sensors typically require exercise for sufficient sweat collection due to low non-exercise secretion rates.
• Existing sensors face challenges in collecting trace sweat amounts for continuous health monitoring in daily scenarios.
• Developing efficient micro-sweat collection methods is crucial for expanding wearable sensor applications.

Purpose of the Study:

• To propose and validate a novel wearable patch for spontaneous and rapid collection of small sweat volumes.
• To overcome the limitations of traditional wearable sweat sensors in non-exercise conditions.
• To enhance the efficiency of sweat collection for in situ colorimetric analyses.

Main Methods:

• A wearable patch inspired by the hierarchical structure of Sarracenia trichomes was designed.
• Microfluidic channels with a 20 μm-wide rib structure were incorporated to maximize capillary force and eliminate sweat hysteresis.
• The patch was tested for its ability to collect trace sweat amounts (0.5 μl) and converge it to a central detection medium.

Main Results:

• The proposed patch demonstrated spontaneous and fast collection of small sweat volumes.
• The microfluidic design effectively utilized capillary force, preventing sweat hysteresis.
• Volunteer verification showed a twofold increase in sweat collection efficiency compared to traditional wearable patches.

Conclusions:

• The developed wearable patch offers an efficient method for collecting trace amounts of sweat.
• This technology holds significant potential for diverse in situ sweat colorimetric analyses in daily life.
• The Sarracenia trichome-inspired design provides a promising platform for next-generation wearable health monitoring devices.