Linear traveling wave motor

The objective of this research is to design and develop a working prototype of a linear traveling wave motor that utilizes THin-layer composite-UNimorph piezoelectric Driver (THUNDER) technology. THUNDER technology is used to create curved actuators (flexures) from piezoceramic wafers. These flexures are arranged alternatively bowed towards and away from a flat surface. The basis of motion rests on the fact that upon actuation the flexures will change both chord length and radius of curvature. This allows the flexures to either grip the driving rod or extend axially. Motion is achieved through sequential operation of individual flexures. This method yields a lightweight actuator with power off holding capability and a larger step size than motors that use stacked actuators. The simple design lends itself to inexpensive fabrication. A finite element model was used to predict the initial curvature and the height displacement of a single flexure. The model takes into account material properties, physical layout, fabrication techniques and driving voltage. These theoretical predictions were compared to experimental results. A prototype was developed but no movement has been realized in this configuration. However, it is shown that the flexures have the capability to achieve step sizes 1-2 orders of magnitude greater than other similar linear actuators.