Non-electric actua­tors offer a promis­ing alter­na­tive for sustain­able and remote opera­tions. My research focuses on the devel­op­ment of thermal micro-actua­tors based on thermo­mag­netic thin films, which harness the intrin­sic mater­ial property of magne­ti­za­tion loss near the Curie temper­a­ture to achieve controlled mechan­i­cal motion. Unlike conven­tional actua­tors that rely on electri­cal stimu­la­tion, these devices operate by thermal trigger­ing, elimi­nat­ing the need for contin­u­ous electri­cal input and thereby reduc­ing power consumption.

Magnetic shape memory alloys such as Heusler alloys, and ferro­mag­netic materi­als like lanthanum-iron-silicon alloys, are commonly classi­fied as thermo­mag­netic materi­als (TM films). These materi­als exhibit changes in magne­ti­za­tion in response to varia­tions in temper­a­ture and magnetic field, making them well-suited for self-actuat­ing mecha­nisms in thermo­mag­netic systems.

The core working princi­ple relies on the thermo­mag­netic effect: when heated above their Curie temper­a­ture (Tc), thermo­mag­netic materi­als lose their magne­ti­za­tion. This shift in magnetic proper­ties can be harnessed to induce movement in a magnet, result­ing in mechan­i­cal actua­tion as shown in Figure 1. The primary advan­tage of these actua­tors lies in their ability to operate without the need for exter­nal electri­cal input, utiliz­ing ambient or waste heat as a power source, thus provid­ing a highly sustain­able approach to actua­tion. At minia­ture scales, the high surface-to-volume ratio facil­i­tates faster heat trans­fer, enabling quicker actua­tion responses.

The project encom­passes the design, micro­fab­ri­ca­tion, and charac­ter­i­za­tion of various actua­tor geome­tries, aiming for increased mechan­i­cal output (force and displace­ment), higher actua­tion frequen­cies, and improved thermal response times upon contact. By enhanc­ing these key perfor­mance metrics, the project seeks to estab­lish thermo­mag­netic actua­tors as viable candi­dates for integra­tion into preci­sion-depen­dent systems. These thermally driven high-force micro-actua­tors have signif­i­cant appli­ca­tion poten­tial in advanced technolo­gies, enabling compact, low-energy actua­tion for soft robot­ics, wireless motion control in biomed­ical tools, and precise thermal tuning in optical and photonic systems.