A Metamaterial-Inspired Sensor for Combined Inductive-Capacitive Detection

In this letter, we introduce a metamaterial-inspired sensor that is capable of performing combined inductive-capacitive sensing, so that both detection and discrimination between metallic and dielectric objects are
accomplished. Metals and dielectrics are distinguished based on their different responses to inductive and capacitive sensing. Both sensing modes are integrated into a single sensing unit, which is developed from an Omega-shaped metamaterial structure. Inductive and capacitive sensing are simultaneously realized when the sensor is operated at off-resonant frequencies. The proposed sensor is fabricated and experimented with metallic and dielectric objects. The measurement results demonstrate the proposed sensor's ability of conducting combined sensing with a range of 10 mm. The performance of proposed sensor is competitive among industrial state of-the-art proximity sensors, yet with added functionality of differentiating metallic and dielectric objects.