Highly Sensitive Textile-Based Capacitive Pressure Sensors Using PVDF-HFP/Ionic Liquid Composite Films

Area of Science:

• Materials Science
• Electrical Engineering
• Textile Engineering

Background:

• Textile-based sensors are crucial for electronic textiles, enabling applications in human-machine interfaces and healthcare.
• Capacitive pressure sensors offer a promising avenue for flexible and wearable sensing technologies.

Purpose of the Study:

• To investigate a textile-based capacitive pressure sensor array utilizing a poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP)/ionic liquid (IL) composite film.
• To optimize the sensor's performance for high sensitivity, stability, and a wide sensing range.

Main Methods:

• Fabrication of a capacitive pressure sensor by embedding Ag-plated conductive fiber electrodes within fabrics.
• Utilizing a PVDF-HFP/IL composite film as the dielectric layer.
• Optimization of the PVDF-HFP:IL ratio to achieve desired sensing characteristics.

Main Results:

• The optimized PVDF-HFP:IL ratio (6.5:3.5) yielded sensors with sensitivities of 9.51 kPa⁻¹ (0-20 kPa) and 0.69 kPa⁻¹ (20-100 kPa).
• The pressure-dependent capacitance variation was attributed to changes in the contact area between electrodes and the composite film.
• A 3x3 sensor array demonstrated multi-point detection capabilities, identifying object positions and weights.

Conclusions:

• The developed textile pressure sensor exhibits excellent performance, suitable for advanced electronic textile applications.
• The sensor's design and materials enable scalable fabrication and multi-point sensing for complex monitoring tasks.
• This work contributes to the advancement of wearable sensing technologies for human-machine interaction and health monitoring.