Visualization of flexural wave propagation in helical coiled ultrasonic waveguide

We have developed a traveling-wave-type miniature ultrasonic motor using a helical coiled waveguide as a stator. In this motor, the elliptical motion of the surface particle due to the flexural ultrasonic waves rotates the rotor, which can be placed adjacently inside or outside the stator, via the frictional force. The rotation of the particle was able to be confirmed like this by searching for the direction of the rotation and the rotation phase in detail. In this study, we present a visualization of the helical coiled waveguide in order to investigate the overall behavior of the coil when the ultrasound has been propagated. Moreover, from the results of the overall behavior of the coal, the local behavior could be confirmed.