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

Highly sensitive, stretchable strain sensors with minimal temperature dependence are essential for precise strain monitoring in human and robotic applications across diverse environments. Although strain sensors with near-zero temperature coefficient of resistance (TCR) have been investigated, achieving high sensitivity while maintaining temperature insensitivity remains a significant challenge. This study proposes a stretchable strain sensor that demonstrates a high gauge factor of 2.3 × 10⁴ and excellent linearity (R² = 0.98), while maintaining temperature insensitivity under applied strain. This performance is achieved through a microcrack architecture formed by stacking a brittle, low-resistance material with a stretchable, high-resistance material with near-zero TCR. The formation of microcracks redirects the current pathway from a low to a high-resistance material. The absolute TCR value remains below 0.1% K^-1 across a strain range of 5%-50%. Furthermore, the peak resistance under 50% cyclic strain fluctuates by only 7% between 25°C and 65°C.