基于背衬层匹配的压电式柔性超声传感器优化  

Optimization of Piezoelectric Flexible Ultrasonic Sensors Based on Backing Layer Matching

作　　者：于永洁 杜昱錡 黄仕磊 甘芳吉[1] YU Yongjie;DU Yuqi;HUANG Shilei;GAN Fangji(School of Mechanical Engineering,Sichuan University,Chengdu 610065,China;School of Electronic Information and Electrical Engineering,Chengdu University,Chengdu 610106,China)

机构地区：[1]四川大学机械工程学院,四川成都610065 [2]成都大学电子信息与电气工程学院,四川成都610106

出　　处：《郑州大学学报（工学版）》2025年第1期98-104,112,共8页Journal of Zhengzhou University（Engineering Science）

基　　金：四川省科技创新创业苗子工程(2021JDRC0090)。

摘　　要：基于聚偏氟乙烯(PVDF)压电薄膜的柔性超声传感器具有体积小、质量轻、易于阵列化等优点,但容易受到背部杂波干扰和阻抗不匹配的影响,导致回波信号频率成分复杂且信噪比较低。为有效吸收传感器背部杂波,提升超声波单向辐射的能力,利用钨粉和硅胶设计针对柔性超声传感器的背衬层,在保持传感器整体柔性的同时使传感器的信号电压幅值提高了200%。其次,根据柔性超声传感器的电学特性提出了柔性超声传感器阻抗匹配优化方法,并通过实验获得最佳匹配参数,使传感器的信噪比从2 dB提高到30 dB。优化后的柔性超声传感器具有宽频带、高频率、窄脉冲的优良性能,对不同曲率、不同壁厚的管道试件厚度的测量实验结果表明其可以达到0.01 mm的精度。Even with the advantages of small size,light weight,and easy matrixing,flexible ultrasonic sensors based on polyvinylidene fluoride(PVDF)piezoelectric film are susceptible to back clutter and impedance mismatching,resulting in a complex frequency component of the return signal and a low signal-to-noise ratio.In order to effectively absorb the stray waves at the back of the sensor and improve the ability of unidirectional radiation of ultrasonic tungsten powder and silica gel were used to design the backing layer for flexible ultrasonic sensors,which could increase the signal voltage amplitude of the sensor by 200%while maintaining the overall flexibility of the transducer.Secondly,according to the electrical characteristics of the flexible ultrasonic sensor,an impedance matching method for flexible ultrasonic sensors was proposed,and the best matching parameters were obtained through experiments,so that the signal-to-noise ratio of the sensor was increased from 2 dB to 30 dB.The optimized flexible ultrasonic sensors had the excellent performance of wide bandwidth,high frequency,narrow pulse.The experimental results of the measurement of the thickness of pipe test specimens with different curvatures and wall thicknesses showed that it could reach the accuracy of 0.01 mm.

关 键 词：柔性超声传感器 背衬层匹配 阻抗匹配 信噪比 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TH89[自动化与计算机技术—控制科学与工程]