Printed ultrasound sensors for enhanced structural health monitoring: development, characterization, and real-time evaluation

This study presents the development of ultrasound (US) sensors for structural health monitoring (SHM) by directly printing the sensors onto structural components. Unlike traditional ultrasound-based SHM systems, this approach minimizes sensor placement and environmental interference challenges, providing a stable, durable, and cost-effective solution for long-term monitoring of critical infrastructure. The core of this technology is a piezoelectric composite made of an OE 132–43/P189 mixture at 80 vol.% ferroelectric particles in a polyimide matrix, selected for its optimal dielectric strength, consistent d 33 polarization, high-frequency response (1–20 MHz), and high thermal stability. Experimental validation showed that the printed sensors effectively measured component thickness in steel and aluminum, confirming their suitability for non-destructive evaluation. Additionally, multi-layer sensor designs were explored, producing higher acoustic pressure at lower operating voltages, enabling applications on thicker materials. This work advances SHM by enabling continuous, real-time monitoring, improving structural safety, and reducing maintenance costs across various industries.