Micropatterned Composite Hydrogel Sheet with Surface Electronic Conductive Network for Ultrasensitive Strain Sensing

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Conductive hydrogels are promising for wearable sensors.
• Existing hydrogels lack sensitivity at small strain ranges.

Purpose of the Study:

• To develop a micropatterned composite hydrogel sheet with enhanced sensitivity.
• To improve wearable sensor performance for detecting subtle movements.

Main Methods:

• Fabricated a micropatterned hydrogel sheet using polyvinyl alcohol/polyacrylic acid crosslinked by Zr4+.
• Constructed a continuous carbon nanotube (CNT) conductive network on the hydrogel.
• Utilized a reverse sandpaper micropattern to induce controlled cracking in the CNT network.

Main Results:

• Achieved ultra-high sensitivity with gauge factors of 76.1 (0-30% strain) and 203.5 (30-100% strain).
• Demonstrated detection of physiological signals, joint bending, hand gestures, and athletic postures.
• The hydrogel sheet exhibited self-healing, adhesiveness, conformability, and stable performance in extreme conditions.

Conclusions:

• The micropatterned structure and controlled cracking mechanism enhance sensor sensitivity.
• This approach offers a viable strategy for designing high-performance wearable electronics.
• The developed hydrogel is suitable for diverse applications requiring sensitive motion detection.