Metamaterial pressure sensor based on ceramic for harsh environments

This paper presents a new type of ultra-material microwave pressure sensor designed for extreme environments, and conducts a systematic study on its structural design, manufacturing process, working mechanism, and experimental performance. The sensor is based on the cross-slot ultra-material resonant structure. Platinum-based conductive patterns are precisely fabricated on a high-purity alumina ceramic substrate through screen printing, and a strong bond between metal and ceramic is achieved through high-temperature sintering. Thanks to the high-temperature stability of the ceramic material and the high precision of the process, this sensor maintains excellent structural integrity and performance consistency in harsh environments. The working mechanism of the sensor is based on the microstructural deformation induced by pressure. When external pressure is applied to the ceramic cavity, the deformation of the cavity will change the equivalent electromagnetic boundary conditions inside, thereby causing perturbations in the resonant modes of the metamaterial, resulting in a continuous measurable shift in the resonant frequency. Based on this mechanism, the change in pressure can be precisely mapped to the frequency change, enabling wireless and passive pressure measurement. By utilizing the intrinsic resonant radiation of the metamaterial to achieve coupled readings, the complexity of sensor integration is significantly reduced and its working reliability in high-pressure, high-temperature, and strong electromagnetic interference environments is improved. During the design stage, the influence laws of the geometric parameters of the metamaterial and other factors on the resonant performance and pressure sensitivity were analyzed through finite element coupling simulation. Experimental verification shows that the sensor exhibits excellent linear pressure response within the range of 0−500 kPa, and maintains good repeatability and frequency stability in the high-pressure zone. The maximum sensitivity reaches 135 kHz/kPa, and the frequency drift is minimal during multiple loading-unloading cycles, fully demonstrating that the structural strength and reliability of the design meet the engineering requirements. The sensor proposed in this study could achieve long-term stable operation in aerospace engine compartments, high-temperature metallurgical furnaces, deep mine pressure monitoring, petrochemical high-corrosion pipelines, and extreme environment equipment. This research not only demonstrated the potential of integrating metamaterials with advanced ceramic processes to construct wireless passive sensors, but also provided new design ideas and process routes for the engineering application of microwave sensing technology in harsh environments.