Ultrasonic drive of small mechanical components on a tapered metal strip

In this report, we demonstrate that small mechanical components such as bars, bar composites, disks and cogwheels, centered at a nodal point of tapered metal strip in flexural ultrasonic vibration, can be ultrasonically driven to rotate by the tapered metal strip. It is experimentally found that revolution speed of the small mechanical components is affected by the metal strip vibration, and the structure and size of the small mechanical components. The revolution speed increases as the metal strip vibration increases and the size of the small mechanical components decreases, and it may be higher than 600 rpm. Measuring the transient response of angular speed, driving torque on the small disk with 4.7 mm diameter and 0.1 mm thickness is estimated to be 0.91 μN m when the driving voltage is 100 Vp–p and the actuator is in resonance. Travelling waves are found around the nodal point of the metal strip, which may be the cause of the rotary drive.

► Small mechanical components can be driven to rotate by vibration node.
► Circumferential travelling waves may exist around a vibration node.
► The speed and amplitude of the travelling waves change with their location.