Development of a Split Ring Resonator Sensor for Vibration Detection

The main focus of this work is the development of a metamaterial-based vibration sensor for the detection of earthquake amplitudes. The sensor is composed of two metamaterial layers made of FR-4 substrates with Circular Split Ring Resonators (CSRR) arranged in a back-to-back configuration on each substrate. The variation of the spacing between the plates results in an alteration of the electric field and thus changes in the resonance frequencies of the whole system. The system is designed and optimized to resonate in the GSM 1.8 GHz band, which ultimately results in a self-sustaining sensor. A clear relationship between the spacing of the two layers and the shift in the resonance frequency has been obtained. It also changes the magnitude of the reflected and absorbed energy from the sensor. This spacing in turn can be directly correlated with the vibration amplitudes. The system can be integrated into a warning system with the ability to quantify the structural resilience of buildings against potentially damaging vibrations. Different unit cell geometries of metamaterial surface are tested before selecting the CSRR geometry to develop highly sensitive sensors operating in the GSM frequency band at 1.8 GHz.