Highly Sensitive and Stretchable MXene/CNTs/TPU Composite Strain Sensor with Bilayer Conductive Structure for Human...

Area of Science:

• Materials Science
• Nanotechnology
• Wearable Technology

Background:

• Wearable strain sensors are crucial for human activity monitoring.
• A key challenge is balancing high sensitivity with a broad working range.
• Existing sensors often compromise one for the other, limiting universal application.

Purpose of the Study:

• To develop a wearable strain sensor with simultaneous high sensitivity and a broad working range.
• To utilize a bilayer-conductive structure for enhanced performance.
• To demonstrate the sensor's capability in monitoring diverse human movements.

Main Methods:

• Fabrication of a Ti3C2Tx MXene/carbon nanotubes (CNTs)/thermoplastic polyurethane (TPU) composite film via vacuum filtration.
• Utilizing a porous electrospun TPU mat as a skeleton.
• Designing a bilayer structure with a brittle upper layer and a flexible lower layer.

Main Results:

• The developed sensor exhibits a broad working range (up to 330%) and high sensitivity (maximum gauge factor of 2911).
• The sensor demonstrates superb long-term durability (2600 cycles at 50% strain).
• Synergistic effects between material components and hydrogen-bonding interactions contribute to performance.

Conclusions:

• The Ti3C2Tx MXene/CNTs/TPU strain sensor overcomes the sensitivity-range trade-off.
• The sensor is successfully applied for monitoring subtle (facial expressions, pulse) and large-scale (limb bending) human movements.
• This technology shows significant promise for advanced wearable devices and human-machine interaction.