Dynamic model for design optimization of a high bandwidth thermal linear motor

This paper presents the model for the design optimization of an aluminum Thermal Linear Motor (TLM) for high bandwidth positioning systems. The aluminum TLM is the crucial driving element for our Hard Disk Drive thermal micro actuator. It occupies less area than an electrostatic actuator with the same driving force while still reaching 3-5 kHz bandwidth for positioning accuracy better than 5 nm. Optimized thermal actuators, as found in literature, improve the stroke versus power consumption by reducing the heat loss to the frame. However, for fast cooling, i.e. fast thermal response, good heat transport to the frame is necessary. This means that a thermal actuator design which is optimal for quasi-static operation is different from a design that is optimal for high bandwidth applications.