A Wearable Strain Sensor Utilizing Shape Memory Polymer/Carbon Nanotube Composites Measuring Respiration Movements

Area of Science:

• Materials Science
• Wearable Technology
• Biomedical Engineering

Background:

• Flexible wearable sensors are crucial for healthcare and human-computer interaction.
• Developing sensitive and durable sensors is essential for advanced applications.

Purpose of the Study:

• To develop and characterize a novel resistive stretch sensor using shape memory polymers (SMP) and carbon nanotubes (CNTs).
• To evaluate the sensor's performance in detecting subtle movements and monitoring human respiration.

Main Methods:

• Fabrication of SMP-CNT composite sensors with and without silver paste coating.
• Characterization using Universal Testing Machine (UTM) and LCR meter.
• Durability testing over 1000 stretching cycles.
• Respiration monitoring using Fourier transform and power spectrum density (PSD) analysis.

Main Results:

• The sensor exhibited high sensitivity with a gauge factor up to 20 at 5% strain.
• The silver coating enhanced sensor performance.
• The sensor demonstrated excellent durability over 1000 cycles.
• Respiration monitoring identified a dominant frequency of approximately 0.35 Hz.

Conclusions:

• The developed SMP-CNT sensor is highly sensitive, durable, and suitable for detecting subtle movements.
• The sensor effectively monitors human respiration, showing potential for personalized healthcare.
• This technology offers a promising platform for next-generation wearable health monitoring systems.