Bionic Wet Adhesive Surface with Micronano Hierarchical Structure for Robust Biosignal Monitoring.

Area of Science:

• Biomimetics and Materials Science
• Adhesion Science
• Wearable Medical Devices

Background:

• Perspiration significantly reduces skin patch adhesion, compromising biosignal monitoring quality.
• Existing medical diagnostic patches lack robust adhesion under wet conditions.
• Need for advanced materials to ensure stable wearable device performance.

Purpose of the Study:

• To design and fabricate a bionic hierarchical patterned surface (HTP) for enhanced wet adhesion.
• To investigate the adhesion mechanisms of the HTP under various wetting conditions.
• To evaluate the HTP's performance in wearable medical device applications, specifically electrocardiogram (ECG) monitoring.

Main Methods:

• Fabrication of a honeybee-treefrog bionic hierarchical patterned surface (HTP) using polydimethylsiloxane (PDMS).
• Systematic evaluation of adhesion performance under different wetting conditions and surface designs.
• Theoretical modeling and experimental validation of adhesion enhancement mechanisms (liquid film self-absorption, air embolism).

Main Results:

• The HTP demonstrated significantly enhanced normal and shear adhesion forces (4-fold and 8-fold increases, respectively) compared to non-patterned surfaces.
• Effective liquid drainage and maintenance of high adhesion force under wet conditions.
• Demonstrated potential for stable electrocardiogram (ECG) monitoring with strong biocompatibility and biosignal detection.

Conclusions:

• The HTP effectively overcomes adhesion challenges caused by perspiration in wearable medical devices.
• Bionic hierarchical patterning offers a promising strategy for improving wet adhesion performance.
• The developed HTP provides a novel solution for reliable biosignal monitoring in wearable technology.