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Wireless crack sensing using an RFID-based folded patch antenna

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review


Original languageEnglish
Title of host publicationBridge Maintenance, Safety, Management, Resilience and Sustainability - Proceedings of the Sixth International Conference on Bridge Maintenance, Safety and Management
Number of pages7
Publication statusPublished - 2012
Publication typeA4 Article in a conference publication
Event6th International Conference on Bridge Maintenance, Safety and Management, IABMAS 2012 - Stresa, Lake Maggiore, Italy
Duration: 8 Jul 201212 Jul 2012


Conference6th International Conference on Bridge Maintenance, Safety and Management, IABMAS 2012
CityStresa, Lake Maggiore


This paper describes the crack sensing performance of a wireless and passive smart-skin sensor designed as a folded patch antenna. When strain/deformation occurs on the patch antenna, the antenna's electrical length changes and its electromagnetic resonance frequency also changes accordingly. An inexpensive off-the-shelf radiofrequency identification (RFID) chip is adopted in the sensor design for signal modulation and collision avoidance. With assistance from the RFID chip, the resonance frequency change can be interrogated and recorded by a wireless reader. The RF interrogation energy from the reader is captured by the patch antenna, and then used to activate the RFID chip that transmits modulated signal back to the reader. Therefore, the interrogation process is wireless and the antenna sensor is battery-free. In this research, crack sensing performance of the antenna sensor is studied and tested by a specially designed crack testing device. Testing results show strong correlation between interrogated resonance frequency and crack opening size.