Magnetic Shape Memory Alloy Actuator for Instrument Applications

This project will develop a simple actuator based on magnetic shape memory alloy (MSMA), a novel new family of crystalline materials which exhibit strain deformation >10% when subjected to a magnetic field. These materials have the unique property of retaining their strained state when the driving field is removed, making them unique in the world of shape memory materials, and desirable as an actuator material as they will maintain position when powered off. MSMA can potentially replace current shape memory alloys in many spaceflight instrument applications, as well as enable new precision mechanism types.

The objective of this project is to develop a simple, small linear actuator system using magnetic shape memory allow capable of self-position sensing and power-off position maintenance. The actuator system will consist of a laboratory bench-top linear actuator, breadboard-level control electronics, and a computer command interface. The effort is a technology maturation of MSMA mechanisms, which are currently at TRL 2/3, and we intend to bring them to TRL 4. Boise State University (BSU) is a research partner and will provide MSMA crystals and contribute design consultation.

The innovative elements of this technology lie in the use of MSMA, which combine many very desirable properties lacking in other shape memory alloy materials. Similar to conventional SMAs, MSMA exhibit a large, reversible shape change related to a crystal structural transformation. Unlike conventional SMAs, which utilize temperature or voltage as the control parameter, MSMAs are driven by a magnetic field. Fields can be applied with very short response times making MSMA-based actuators kHz capable. Furthermore, the magnetic-field-induced deformation is permanent, and reversible. Holding a constant position does not require power. Also, positioning is highly precise with accuracy in the nanometer range. These properties of MSMA-based actuators will increase the accuracy of earth and space science instruments and reduce operational power consumption.