Research on specific identification method of substances through terahertz metamaterial sensors

In this work, a strategy to specifically identify substances through correlating the substance fingerprint peak with the resonant frequency shift of the metamaterial sensors has been presented and demonstrated experimentally. Three metamaterial sensors with different resonance frequencies were fabricated by ultrafast laser direct writing, and they all have good sensing performance. Due to the different matching degrees between the sensor resonance peak and the substance fingerprint peak, different frequency shifts of the sensor resonance peak were obtained. The better the fingerprint peak matches the sensor resonance peak, the greater the shift of the sensor resonance peak. On the contrary, the smaller shift will be obtained. Through this method, the correlation between the resonant frequency shift of the sensor and the fingerprint peak of the substance is developed. Thus, within a certain range of some unknown substances, the fingerprint peak positions of the substances can be deduced through the frequency shifts of the sensor. This phenomenon was used for the specific identification of the substances. This study provides a new idea for the specific detection of the substances by the metamaterial sensor.