Design And Experimental Research Of Reconfigurable Liquid Metal Antenna

As a key instrument that directly obtains the magnitude and distribution of internal stress,pressure sensors are widely used in many industries such as medical appliances,transportation,aerospace,and environmental testing.In the field of geotechnical engineering,pressure sensors also play an important role.However,the traditional pressure sensors currently used in actual projects are usually wired,and most of the internal sensitive components are made of rigid materials,which are prone to failures such as mechanical brittle fracture.Therefore,designing a flexible sensor capable of wireless transmission has important significance and application value in engineering.This paper uses soft lithography technology to etch PDMS(polydimethylsiloxane)into a microfluidic chip as the base material,and encapsulate liquid metal into the microfluidic chip to produce a liquid metal antenna as a pressure sensor.Thanks to the high elasticity of the PDMS material and the unique self-healing ability of the liquid metal in the microfluidic channels,the resonance frequency of the liquid metal antenna under pressure is reconfigurable and has certain flexibility characteristics.The combination of radio frequency technology realizes wireless sensing of physical quantities.In this paper,a sensor chip with a frequency reconstruction range of2.159GHz?2.450GHz and a monitoring pressure range of 0N?540N is designed and manufactured,and a self-designed"T-shaped"shell is installed on this basis,which overcomes the traditional steel The shortcoming of uneven shell deformation,expand the range of the sensor chip to 0k N?96k N.The liquid metal antenna was used to carry out physical tests,load step by step,analyze the relationship between the antenna resonance frequency and pressure load,and compare and discuss the measured data,software simulation,and theoretical calculation in detail.The results show that the three sets of data have a good degree of fit under linear fitting,and there is a good linear relationship between the pressure load and the resonance frequency,so the functional relationship can be established based on the fitting model,and the liquid metal antenna As a pressure sensor.The results show that the three sets of data have a good degree of fit under linear fitting,and there is a good linear relationship between the pressure load and the resonance frequency,so the functional relationship can be established based on the fitting model,and the liquid metal antenna As a pressure sensor;A cyclic loading and unloading experiment was carried out,and different loading rates were used to explore the impact on the performance of the sensor,and the loading-unloading characteristic curve and the influence characteristic curve of the loading rate were drawn.Experimental results show,the repeatability error?and the return error?in the cyclic loading and unloading experiment are very small,which means that the sensor does not produce residual deformation during the cyclic loading and unloading process;Experiments on the influence of temperature on the performance of the sensor are carried out,and the temperature sensitivity and stability during the experiment are calculated.The results show that the temperature brings greater error to the sensor.The higher the temperature,the worse the sensor's sensitivity.During use,it is necessary to correct the temperature factor;An exploratory experiment using nylon material to replace PDMS,which is a traditional base material,was carried out.The results show that nylon material is more affected by temperature.Finally,the application of the reconfigurable liquid metal antenna in slope stability monitoring and foundation pit monitoring is prospected.