Two-dimensional alignment and displacement sensor based on movable broadside-coupled split ring resonators

• Published in: Sensors and actuators. A. Physical. Vol. 210; pp. 18 - 24
• Main Authors: Horestani, Ali K., Naqui, Jordi, Shaterian, Zahra, Abbott, Derek, Fumeaux, Christophe, Martín, Ferran
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2014
• Subjects: Alignment sensor; Displacement sensor; High dynamic range; Metamaterials; Two-dimensional; Metamaterials; High dynamic range; Alignment sensor; Displacement sensor; Two-dimensional
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2014.01.030

•A 1D displacement sensor based on a microstrip line loaded with broadside-coupled split-ring resonators is presented.•A modified resonator geometry extends the concept to realize a 2D displacement sensor with high dynamic range.•The principle of operation of the sensors is based on a shift in resonance frequency caused by a break of symmetry.•The mode of operation makes the sensor highly immune to environmental noise and changes in temperature.•The proposed sensors detects break of symmetry and thus can be used as alignment sensors as well. This paper proposes a two-dimensional alignment and displacement sensor based on movable broadside-coupled split ring resonators (BC-SRRs). As a basis for this sensor, a one-dimensional displacement sensor based on a microstrip line loaded with BC-SRRs is presented firstly. It is shown that compared to previously published displacement sensors, based on SRR-loaded coplanar waveguides, the proposed one-dimensional sensor benefits from a much wider dynamic range. Secondly, it is shown that with modifications in the geometry of the BC-SRRs, the proposed one-dimensional sensor can be modified and extended by adding a second element to create a high-dynamic range two-dimensional displacement sensor. Since the proposed sensors operate based on a split in the resonance frequency, rather than the resonance depth, they benefit from a high immunity to environmental noise. Furthermore, since the sensors’ principle of operation is based on the deviation from symmetry, they are more robust to ambient conditions such as changes in the temperature, and thus they can be used as alignment sensors as well. A prototype of the proposed two-dimensional sensor is fabricated and the concept and simulation results are validated through experiment.