Design And Characterization Research Of Thermally Tunable Metamaterials Based On Liquid Metals

As an artificial structure,metamaterials can choose suitable materials for substrates according to different applications.By designing electromagnetic structural units or arrays with different shapes,sizes and rotation directions,the amplitude,phase,polarization direction and other characteristic parameters of the incident electromagnetic wave can be controlled as needed.Leading to the realization of novel planar functional devices and systems,such as new high-performance spatial filter,beam control device,focusing lens,holographic imaging,etc.which has been widely concerned in the fields of electronics,optics and other technical fields.Tunable metamaterials based on elastic and fluid substrates as well as fluid metamaterials have shown obvious technical and performance advantages in dynamic tuning and on-demand tuning,which has became a new hot research direction in the field of metamaterials.However,there are still many key technical problems and research gaps in nonlinear coupling effect of fluid metamaterials.Thus,the working mechanism,design and analysis methods of thermally tunable metamaterials based on liquid metals were studied in this paper,Key technologies of thermal reconfigurable tuning/nonlinear coupling analysis theory,numerical simulation method,manufacturing technique and testing method were innovatively explored.The tuning mechanism and application were verified by experimental study.The research details and contributions are shown as follows:1.Based on the analysis of Fano,EIT,Anapole,ELC four resonant modes and its mechanism of high Q factors,four kinds of high Q factors thermally tunable metamaterials unit based on liquid metals has been designed,The measured average resonance Q factors of the designed Anapole structure can reach 240,the measured thermally tunable sensitivity of the designed EIT structure can reach 17.12MHz/?,and the measured FOM value can reach 1.09/?.2.By Using the full-wave electromagnetic simulation software HFSS based on the finite element,the thermally tunable characteristics data of four resonant modes of thermally tunable metamaterials based on liquid metals were obtained by numerical simulation.The rectangular waveguides were used as the test environment,and experiment platforms were built to test the resonant characteristics of metamaterial structural elements under different temperature.The reconfigurable mechanism of thermal reconfigurable tuning of thermally tunable metamaterials based on liquid metals was tested and verified.3.Based on the theory of electromagnetism and thermology,the mechanism of electromagnetic waves heating and heat transmission of ELC mode thermally tunable metamaterials based on liquid metals were analyzed,and the multi-physical nonlinear coupling model of thermally tunable metamaterials based on liquid metals was established.By using COMSOL Multiphysics,the simulation of electromagnetic waves heating and nonlinear coupling effect excited by different power incident electromagnetic waves were completed.Combined with data fitting,the nonlinear coupling and tuning mechanism were revealed.Experiment platform was built to verify the nonlinear characteristics.The research results of this paper have developed a technical system for the nonlinear coupling and tuning mechanism of thermally tunable metamaterials based on liquid metals,which has significant scientific significance and engineering value.