Thermomagnetic Microactuators

Microactuators are miniaturized mechanical devices that convert electrical, thermal, or magnetic energy into controlled motion. They are critical components in microelectromechanical systems (MEMS) and are widely used in applications requiring precision actuation at small scales. Thermomagnetic and shape memory microactuators provide high work density and efficient energy utilization, making them particularly attractive for microactuation concepts.

Bistable microactuators offer a significant advantage over monostable systems by maintaining stable positions without continuous power input. Our devices leverage ferromagnetic materials exhibiting sharp magnetization changes at Curie Temperautre (T_c) categorized as thermomagnetic (TM) materials and SMA-based microactuators with high work density. By integrating TM and SMA elements, we achieve switchable magnetic latching within a narrow temperature range, enabling rapid and efficient bistable actuation with minimal energy consumption. This makes it very interesting for applications where compactness and large stroke is important like in the case of refreshable Braille displays.

In the first prototype utilizing a miniature peltier module for maintaining the temperature of LaFeSi plate, the device demonstrated bistable actuation and further scaling down of size and novel heat transfer mechanism to avoid peltier device is being carried out currently.