Highly Sensitive Porous PDMS-Based Capacitive Pressure Sensors Fabricated on Fabric Platform for Wearable...

Area of Science:

• Materials Science
• Sensor Technology
• Biomedical Engineering

Background:

• Capacitive pressure sensors are crucial for monitoring physical interactions.
• Optimizing dielectric properties is key to enhancing sensor performance.
• Applications in sports require robust, wide-range pressure sensing capabilities.

Purpose of the Study:

• To fabricate a novel porous polydimethylsiloxane (PDMS)-based capacitive pressure sensor.
• To optimize dielectric layer porosity for wide-range pressure sensing in sports.
• To demonstrate the sensor's application in a wearable helmet fit cap.

Main Methods:

• Fabrication of porous PDMS dielectric layers using nitric acid (HNO3) and sodium hydrogen bicarbonate (NaHCO3) to generate CO2 gas.
• Systematic variation of curing temperature, HNO3/PDMS concentration, and PDMS mixing ratio to control porosity and dielectric properties.
• Characterization of sensor response across a wide pressure range (0-1000 kPa).

Main Results:

• Increased curing temperature, HNO3 concentration, and PDMS ratio led to higher porosity and enhanced sensitivity.
• Relative capacitance changes up to ~485% were achieved by optimizing fabrication parameters.
• The optimized sensor (PS9) demonstrated high sensitivity in both low (<50 Pa) and high (0.2-1 MPa) pressure ranges.

Conclusions:

• Optimizing dielectric layer porosity in PDMS-based capacitive sensors significantly improves sensitivity for wide-range pressure detection.
• The developed sensor technology is suitable for demanding sports applications.
• A wearable pressure mapping system for helmet fit was successfully demonstrated.