Wireless Displacement Sensing Enabled by Metamaterial Probes for Remote Structural Health Monitoring
Burak Ozbey,
Emre Unal,
Hatice Ertugrul,
Ozgur Kurc,
Christian M. Puttlitz,
Vakur B. Erturk,
Ayhan Altintas,
Hilmi Volkan Demir
Affiliations
Burak Ozbey
Department of Electrical and Electronics Engineering, Department of Physics, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara TR-06800, Turkey
Emre Unal
Department of Electrical and Electronics Engineering, Department of Physics, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara TR-06800, Turkey
Hatice Ertugrul
Department of Electrical and Electronics Engineering, Department of Physics, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara TR-06800, Turkey
Ozgur Kurc
Department of Civil Engineering, Middle East Technical University, Ankara TR-06800, Turkey
Christian M. Puttlitz
Department of Mechanical Engineering, School of Biomedical Engineering, Department of Clinical Sciences, Colorado State University, Ft Collins, CO 80523, USA
Vakur B. Erturk
Department of Electrical and Electronics Engineering, Department of Physics, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara TR-06800, Turkey
Ayhan Altintas
Department of Electrical and Electronics Engineering, Department of Physics, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara TR-06800, Turkey
Hilmi Volkan Demir
Department of Electrical and Electronics Engineering, Department of Physics, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara TR-06800, Turkey
We propose and demonstrate a wireless, passive, metamaterial-based sensor that allows for remotely monitoring submicron displacements over millimeter ranges. The sensor comprises a probe made of multiple nested split ring resonators (NSRRs) in a double-comb architecture coupled to an external antenna in its near-field. In operation, the sensor detects displacement of a structure onto which the NSRR probe is attached by telemetrically tracking the shift in its local frequency peaks. Owing to the NSRR’s near-field excitation response, which is highly sensitive to the displaced comb-teeth over a wide separation, the wireless sensing system exhibits a relatively high resolution (<1 µm) and a large dynamic range (over 7 mm), along with high levels of linearity (R2 > 0.99 over 5 mm) and sensitivity (>12.7 MHz/mm in the 1–3 mm range). The sensor is also shown to be working in the linear region in a scenario where it is attached to a standard structural reinforcing bar. Because of its wireless and passive nature, together with its low cost, the proposed system enabled by the metamaterial probes holds a great promise for applications in remote structural health monitoring.
