Development of a flexible piezocomposites surface acoustic wave　sensor

摘要

Surface acoustic wave (SAW) sensor has increasing demand in structural health monitoring due to its passive, reliablelife-cycle, high accuracy, and small size. The ongoing demands of sensor’s adaptability with flexible substrates, whichis capable of wireless monitoring, is the basis of the research. The SAW device assembly includes a piezoelectriccomposite substrate that aids in wave transmission and two interdigital transducers (IDTs) capable of actuating andsensing radio frequency (RF) signals. The SAW substrate is fabricated by integrating lead zirconate titanate ceramicnanoparticles into polyvinylidene fluoride polymer matrix using dimethyl sulfoxide as the solvent. Hot-pressing themixtures produces a thin 0-3 composite substrate that exhibits flexibility and optimum dielectric properties. Thesubstrate material properties are studied by conducting FTIR scanning. Delay-line IDTs are incorporated on thesurface of the substrate by a conventional photolithographic technique. With the sensor fabricated, RF signals arepassed onto the device through the input transducer generating Rayleigh waves. The transmission and reflectioncharacteristics of the device is determined through the S-parameter reading obtained using a network analyzer. Thispaper discusses about the development process of a flexible piezocomposite SAW sensor.