Flexible Transparent Films of Oriented Silver Nanowires for a Stretchable Strain Sensor

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Stretchable strain sensors are crucial for wearable electronics but face challenges in sensitivity and durability.
• Existing sensors often struggle with practical application requirements.

Purpose of the Study:

• To develop a highly sensitive and durable stretchable strain sensor for practical applications.
• To investigate the relationship between silver nanowire orientation and sensor performance.

Main Methods:

• Fabrication of a stretchable conductive film using silver nanowires (AgNWs) embedded in a patterned polydimethylsiloxane (PDMS) substrate via rod coating.
• Characterization of the sensor's strain resistance variation based on nanowire orientation angles (0°, 60°, 90°).
• Verification of sensor stability using a sandwich structure PDMS/AgNW/Pat-PDMS configuration.

Main Results:

• The sensor demonstrated high sensitivity with a gauge factor (GF) of 15 within ~120% strain.
• Achieved superior durability with 20,000 bending cycles and 5000 stretching cycles.
• Exhibited excellent response to bending, attributed to nanowire separation and current path geometry changes.

Conclusions:

• The developed AgNW/Pat-PDMS stretchable strain sensor offers a promising solution for wearable electronics.
• Controlling nanowire orientation provides a method for precise strain regulation and enhanced sensor performance.
• The sensor's high sensitivity, durability, and bending response meet practical application demands.