Hierarchically Constructed Liquid Metals for Sensitive Detection of High-Frequency Subtle Vibrations

Area of Science:

• Materials Science
• Wearable Technology
• Sensor Technology

Background:

• Wearable sensors struggle with complex dynamic environments, hindering subtle vibration detection.
• Coupled output signals from varying strains complicate accurate measurements.

Purpose of the Study:

• To develop a fibrous strain sensor for sensitive detection of high-frequency subtle vibrations.
• To enable accurate monitoring in challenging dynamic strain conditions.

Main Methods:

• Hierarchically constructed liquid metals (LMs) integrated into a fibrous sensor.
• Multi-layered structure: continuous LM (CLM) exterior, packed LM particle (LMP) middle, LMP nodules core.

Main Results:

• Achieved an ultralow detection limit of 0.01% (5 μm strain) and a 50 ms response time.
• Demonstrated high linearity (≈0.999) over a wide strain range (up to 250%).
• Successfully recorded intense body movements, microstrains, damping, acoustic vibrations, and walking tremors.

Conclusions:

• The novel LM fibrous sensor offers high sensitivity and accuracy for subtle vibration detection.
• This technology advances wearable devices for comprehensive physical activity and physiological monitoring.