Long-Term Stable Flexible Strain Sensor Fabricated by Constant Hysteresis.

Area of Science:

• Materials Science
• Biomedical Engineering
• Nanotechnology

Background:

• Long-term stability is critical for wearable and implantable medical devices, yet challenges like mechanical deformation and body fluid erosion hinder commercialization.
• Flexible electronic devices require robust performance under continuous physiological activity for reliable health monitoring.

Purpose of the Study:

• To develop a hierarchical AgNWs-P3HT/PDMS-based flexible strain sensor with enhanced long-term stability and performance.
• To evaluate the sensor's sensitivity, strain range, shape-plasticity, biocompatibility, and applicability in physiological monitoring.

Main Methods:

• Fabrication of a hierarchical AgNWs-P3HT/PDMS-based flexible strain sensor.
• 80-day experimental assays to assess long-term stability and gauge factor (GF) sensitivity.
• Cytotoxicity assay using human corneal epithelial cells to evaluate biocompatibility.
• Testing the sensor's response to physiological pressure and diverse movement actions.

Main Results:

• The flexible strain sensor exhibited long-term stability with no statistical difference in gauge factor (GF) sensitivity over 80 days.
• Achieved high GF-sensitivity (151.1) with a thin composite electrode (0.2 mm) and a wide strain response range (0.1-40%).
• Demonstrated excellent biocompatibility and shape-plasticity for integration into devices like contact lenses.
• Successfully realized physiological pressure monitoring and diverse movement action detection.

Conclusions:

• The hierarchical AgNWs-P3HT/PDMS-based flexible strain sensor offers a stable and reliable solution for health monitoring applications.
• The sensor's performance, biocompatibility, and adaptability make it a promising candidate for commercial wearable and implantable medical devices.
• This work addresses key challenges in flexible electronics, paving the way for advanced physiological monitoring systems.