Ultra Shear Forces use a combination of  an out of plane (or bending) vibration mode with an in-plane (or lateral) one to create a local elliptical motion of the top surface of a plate. In the following video, we depicted the bending mode (AN), the lateral mode (AL) and the combination of both.

An ultrasonic generator is designed. By choosing shape and dimension, it is possible to have a lateral vibration mode at the same frequency of the nomal vibration mode. A specific control algorithm can synchronize both modes, hence achieving the elliptical motion.