Piezoelectric Paint Sensor for Nondestructive Structural Condition Monitoring

This article presents a novel piezoelectric paint-based structural condition monitoring method. The piezoelectric paint concerned is composed of tiny piezoelectric particles mixed within polymer matrix. A special fabrication technique has been developed to apply large area of piezoelectric paint directly onto the surface of host structures in an efficient manner. Because of the electro-mechanical coupling properties of piezoelectric paints, the vibration responses of host structures can be monitored by measuring the output voltage signals from the piezoelectric paint sensor. Additionally, a novel surface crack detection technique has been conceived and validated experimentally, in which cracks of the host structure is detected by observing the measured signals from a piezoelectric paint sensor with multielectrode configuration. Piezoelectric paint has a high potential for replacing conventional coating materials by integrating structural health prognostic and diagnostic functions with the functionalities of conventional coating materials such as corrosion protection and decoration. Most appealing is that piezoelectric paints would serve multiple functions – it can simultaneously measure dynamic strain caused by structural vibration while monitoring cracks at the sensor location. This promising structural health monitoring technique is believed to be useful in many important applications including nondestructive structural condition prognostic and diagnostic of aircraft structures, naval ships and large-scale civil structures.