Highly Sensitive and Temperature-Insensitive Stretchable Strain Sensor with Microcrack-Engineered Architecture.

Area of Science:

• Materials Science
• Sensor Technology
• Mechanical Engineering

Background:

• Highly sensitive and stretchable strain sensors are critical for human and robotic applications.
• Minimizing temperature dependence in strain sensors is a persistent challenge, despite research into near-zero temperature coefficient of resistance (TCR).

Purpose of the Study:

• To develop a stretchable strain sensor with high sensitivity and minimal temperature dependence.
• To address the challenge of achieving both high sensitivity and temperature insensitivity in strain sensors.

Main Methods:

• Fabrication of a stretchable strain sensor using a microcrack architecture.
• Stacking a brittle, low-resistance material with a stretchable, high-resistance material exhibiting near-zero TCR.
• Analysis of current pathway redirection due to microcracks.

Main Results:

• Achieved a high gauge factor of 2.3 × 10^4 and excellent linearity (R^2 = 0.98).
• Demonstrated temperature insensitivity with absolute TCR below 0.1% K^-1 across 5%-50% strain.
• Observed only a 7% resistance fluctuation between 25°C and 65°C under 50% cyclic strain.

Conclusions:

• The proposed microcrack architecture effectively enables highly sensitive and temperature-insensitive stretchable strain sensing.
• This sensor design offers a promising solution for precise strain monitoring in diverse environmental conditions.
• The sensor's performance indicates significant advancements for wearable electronics and robotics.