Electrically Controlled Of Liquid Metal And Its Reconfigurable Antenna Radiation Performance

Reconfigurable technology is critical to the future of wireless sensing and communications.Current reconfigurable technologies can only achieve a limited number of reconfiguration states and are inherently limited.Gallium-based liquid metals are concerned by the field of reconfigurable electronic devices due to their excellent flowability and conductivity at room temperature,and their safety and non-toxicity.In existing applications,pneumatic control is used to control liquid metal,for which a large micropump is required.In this thesis,a method using only the potential was proposed to drive liquid metal,and successfully verified by fabricating the antenna.Here,Ga_68.5In_21.5Sn₁₀ liquid metal was selected as model materials.continuous electrowetting and electrochemically controlled capillarity of liquid metal were systematically studied.The influence of voltage,electrolyte concentration,channel width,electrode interval,and droplet mass on electrochemically controlled capillarity and the influence from voltage on continuous electrowetting are studied by controlled variable method.Two mechanisms of Electrically controlled are proposed.The liquid metal reconfigurable symmetrical vibrator antenna was designed by Electrochemically Controlled Capillarity.The radiation performance of the antenna was studied.Using a high-speed camera and Image J software,the area change was analyzed for the case of the droplet on the PDMS basement.It is concluded that the area of liquid metal can become smaller?or larger?by removing?or depositing?an oxide film in the unconstrained channel.The video and image of other experiments were also collected by high-resolution camera.By analyzing the motion parameters such as droplet movement speed and displacement,continuous electrowetting can be obtained.The droplet movement rate is positively correlated with the voltage within a certain range.The change in the displacement occurs for the liquid droplet whereas the length does not change dramatically.When the droplet is located in the reservoir on one side of the channel,the DC bias voltage induces droplet to enter the connected microscale channel,thereby causing a change in the length.The droplet deformation speed is proportional to the vo ltage and electrolyte concentration.In the large scale range,the droplet deformation speed is inversely proportional to the channel width.When the thickness is less than or equal to 1 mm,the variation law is opposite.Overall,the droplet deformation rate is inversely proportional to the electrode spacing and droplet mass,but the droplet of 0.75g exhibits the slowest deformation rate.It is finally determined that it is appropriate to design the antenna in a channel with a droplet mass of 0.75 g,a voltage of 7 V,an electrolyte concentration of 1 mol/L,and a 1mm wide channel,and the electrode spacing needs to be selected according to the design frequency.The single-channel capillary adjustment of the liquid metal is developed into a two-way control,and the surface tension of the liquid metal can be independently adjusted in two opposite directions to achieve a synergistic change in the length of the antenna.Such Electrically controlled structure is improved to a system driven by a symmetrical vibrator antenna system.Using the vector network analyzer to test the frequency performance of the antenna,the operating frequency,bandwidth,relative bandwidth,resonant frequency and other parameters of the electrically driven liquid metal antenna at different lengths are obtained,and the specific relationship between the resonant frequency and the antenna length is established.The bandwidth of 1%and 25%and the frequency reconfigurable of1.60-2.51GHz is achieved.This multi-directional control of liquid metal creates a more flexible structural topology that is instructive for later reconfigurable device designs.Finally,the development prospects and limitations of electric drive liquid metal antennas are prospected.