Ultrasounds are a great tool for defects detection particularly for optically non-transparent materials. Hence, working at very high frequency (#GHz) allows the detection of nanoscale contact defects at the interface between two materials and especially in the presence of air, which has negligible acoustic impedance, making it possible to achieve very high sensitivity. For several years, we have been using the high frequency acoustic method for the wetting evaluation of nanostructures in our laboratory. In close collaboration with STMicroelectronics company, we deal with the study of wetting state in the context of wet cleaning processes optimization in the microelectronics industry. Within this perspective and in order to reach these very high frequency ranges, ZnO piezoelectric transducers were developed and integrated on samples to be studied. Thanks to a dedicated workbench, the dynamic of the wetting and drying phenomena have been achieved on high-aspect-ratio nanostructures with liquid solutions having different surface tensions.