一种应用于探测混合液体媒质微小介电变化的实验系统

An Novel Experimental System for Detecting Small Dielectric Changes in Mixed Liquid Media

随着微波非侵入式测量技术的高速发展,微波平面谐振电路因其具有高可靠性、高性能等特点被广泛应用于液体组分精确测量领域。提出一种基于微带结构的对称型射频电路,该电路包括一对正面开口环谐振器(SRR)、多交指电容(IDC)和背面蚀刻的互补开环谐振器(CSRR),在微带线电场强度最大的区域刻蚀CSRR,从而提高测量灵敏度,并基于该电路设计了材料介电特性微小变化非侵入式测量实验系统。为进一步解决常规平面传感器载物台结构复杂、测量需要精确控制液体体积等问题,提出一种3D打印溶液装载结构,利用微流体控流装置实现待测溶液的精确控制和便捷更换。通过对该检测电路加工测试,利用不同浓度的乙醇水溶液标准检测液实时非侵入式测量,并利用神经网络算法对不同浓度的乙醇溶液进行测量,结果与文献值吻合的很好,相对误差可控制在5%以内。证明该微波电路对混合溶液材料浓度微小变化探测的高灵敏度和可靠性。

With the rapid development of microwave nondestructive testing technology,microwave planar resonant circuits are widely used in the field of precise measurement of liquid components due to their high reliability and better perform-ance.A symmetrical radio frequency circuit based on a microstrip structure is proposed,which includes a pair of front split ring resonators(SRR),multiple interdigitated capacitors(IDC)and complementary split ring resonators(CSRR)etched on the back.The CSRR is etched in the region with the largest electric field intensity of the strip line,so as to improve the measurement sensitivity.Further,a nondestructive detection experimental system for small changes in the dielectric proper-ties of materials is designed.In order to solve the problems including the complex structure of the conventional planar sen-sor stage,the volume of the tested liquid solution is difficult to control,a 3D printing solution loading structure was pro-posed,using a microfluidic flow control device to achieve precise control and convenient replacement of the solution to be tested.Through the processing and testing of the detection circuit,the real-time non-destructive detection of the standard detection solution of ethanol aqueous solution with different concentrations proves the high sensitivity and reliability of the microwave circuit for the detection of small changes in the concentration of the mixed solution material.