Load‐Bearing Piezoelectric Integrated Device with Inherent Stress Monitoring Capabilities

Abstract The structural‐functional integrated device optimizes the synergy between mechanical strength and functionality through advanced material design, offering broad application potential. In this work, a novel structural‐functional integrated device designed to address the challenge of stress monitoring in fiber‐reinforced composites is presented. By incorporating potassium sodium niobate piezoelectric material into carbon fiber‐reinforced polymer composites, a load‐bearing and piezoelectric integrated device is successfully developed. The device exhibits outstanding flexural strength of 377.7 MPa and a flexural modulus of 18.8 GPa, making it suitable for use as a structural material. Simultaneously, the device possesses intrinsic piezoelectric properties and can function as a mechanical sensor, demonstrating a linear voltage output over an exceptionally wide pressure range from 10 to 3.8 × 10⁴ N, which enables the monitoring of mechanical stress in the device. Through a carefully designed pattern of carbon fiber fabric, the device can also intelligently identify the location and magnitude of the applied pressure. This research achieves the integration of high mechanical strength and stress sensing functionality through material design, opening new avenues for the development and application of smart composite materials.