Highly Sensitive and Color Adaptable Polyurethane-Based Strain Sensors with Embedded Silver Nanowires

Wearable strain sensors are expected to meet the requirements of high sensitivity, facile fabrication, and high aesthetics to realize practical applications. However, reported sensitive strain sensors fail to exhibit multicolor due to high light absorption. Herein, a flexible strain sensor with high sensitivity and color-exhibition ability is fabricated by half-embedding silver nanowires (AgNWs) into dyeable thermoplastic polyurethane (TPU) films through thermal annealing. A sheet resistance of 11.5 omega sq(-1) and a transmittance above 79.9% at 550 nm is obtained for intact AgNWs/TPU films. A gauge factor of 34 797 is achieved at a tensile strain of 9%, indicating the high sensitivity for monitoring tiny movement changes. Besides, the high transparency allows color exhibition after dying. The multicolor AgNWs/TPU films are further rolled into rod-shaped yarns and weaved with commercial yarns to form wearable colorful electronics.