A Stretch-Insensitive Pressure Sensor Based on Liquid Metal Composite with a Hierarchical Conductive Network

Area of Science:

• Materials Science
• Sensor Technology
• Biomedical Engineering

Background:

• Stretchable pressure sensors are crucial for human-body and soft-robotics applications.
• In-plane stretching significantly degrades sensor performance by altering electrical properties and structure.
• Existing sensors struggle with maintaining accuracy under dynamic stretching conditions.

Purpose of the Study:

• To develop a stretch-insensitive pressure sensor (SIPS) overcoming limitations of current technologies.
• To enhance the stability and reliability of pressure sensing on deformable surfaces.
• To enable accurate monitoring of physiological signals and human-environment interactions.

Main Methods:

• Fabrication of a liquid metal composite (LMC)-based sensor with a hierarchical conductive network.
• Integration of a pyramid dielectric layer with a strain-distribution design.
• Characterization of sensor performance under various stretching strains (0%–150%).

Main Results:

• The LMC electrodes exhibited highly stable resistance (<5% variation) under 0%–150% strain.
• The dielectric layer experienced minimal strain (10% at 100% stretch), ensuring consistent capacitance-pressure response.
• The SIPS accurately monitored physiological signals and human-environment interactions when attached to skin.

Conclusions:

• The developed SIPS demonstrates exceptional stretch insensitivity and stable performance.
• This technology offers a promising solution for reliable pressure sensing on curved and deformable surfaces.
• The SIPS has significant potential for applications in wearable electronics, healthcare, and robotics.