Wireless Displacement Sensing Enabled by Metamaterial Probes for Remote Structural Health Monitoring

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Ozbey B., Unal E., Ertugrul H., KURÇ Ö., Puttlitz C. M., ERTÜRK V. B., ...More

SENSORS, vol.14, no.1, pp.1691-1704, 2014 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 14 Issue: 1
  • Publication Date: 2014
  • Doi Number: 10.3390/s140101691
  • Journal Name: SENSORS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1691-1704
  • Keywords: displacement sensor, metamaterial, structural health monitoring
  • Middle East Technical University Affiliated: Yes


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 mu m) and a large dynamic range (over 7 mm), along with high levels of linearity (R-2 > 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.