Carbon-based printed strain sensor array for remote and automated structural health monitoring

The development of new technologies that incorporate strain sensors for reliable collection of relevant information on the state of civil structures is gaining attention. In this study, an array of 25 printed strain sensors made of inexpensive carbon-based materials is demonstrated. The sensors were incorporated into a flexible substrate with a double-sided copper wiring system. The laboratory tests revealed that the sensors have a gauge factor of 3.27. Moreover, these are highly effective in compensating for temperature variations owing to the full Wheatstone bridge configuration. Two sensor arrays equipped with a wireless data acquisition system that provides automated and remote measurements were deployed on a highway bridge for a five-month-long field test. The collected results revealed the versatility of the printed sensors for various applications within the framework of structural health monitoring (SHM), including the detection and monitoring of defects as well as quantitative analysis of traffic. The sensors demonstrate long-term durability and therefore, the potential for practical application in SHM.