Circuit Model of NFC-Powered Systems for Monitoring Cracks in Built Cultural Heritage

Cracks occurrence and propagation are among the most common problems that affect building construction safety and longevity. In built cultural heritage, these cracks are especially critical due to the construction's historical, cultural, architectural, and aesthetic value. To preserve the structural integrity and impact for future generations, it is essential to monitor cracks. This work discusses the design and simulation of the circuit model for an affordable and wireless system for monitoring surface cracks in construction. The system uses a waterproof resistive strain gauge that is bonded to the test specimen to monitor cracks. Near-field communication (NFC) technology is used for transmitting data wirelessly and powering through energy harvesting. An NFC reader, such as an NFC-enabled smartphone application, monitors the crack's behaviour by tapping it over the strain gauge sensing circuit. The system benefits from the lightweight and flexibility of the strain gauge, satisfying the necessity of maintaining a high level of delicacy in dealing with culturally valued materials. The strain gauge does not apply strain on the material when bonded with the surface. Moreover, the battery-free feature makes the system more dynamic and durable for monitoring various localised spots. This system is aligned with the precaution of not bringing corrosive materials into the vicinity of culturally valued materials.