Development of Single Crystalline Ni-Mn-Ga Foil Microactuators

Magnetic Shape Memory Microactuators

“…Subsequent thinning to the desired thickness is performed by a series of mechanical and chemo-mechanical polishing steps [9] or grinding and electrochemical polishing [10]. Minimum foil thicknesses have been prepared down to about 50 µm.…”

“…Major challenges are related to the control of phase formation and microstructure during film deposition [14]. Different thermo-magneto-mechanical training methods have been investigated to improve the microstructure of as-deposited films [14] and thinned foils [9] in order to reduce the twinning stress and improve TB (Twin boundary) mobility. Instead of using the MSM effect for actuation, a number of alternative actuation concepts have been investigated as will be discussed in Section 3.…”

“…The influence of defects on the mobility of twin boundaries can be reduced by training of the MSMA material. Different methods of thermo-magneto-mechanical training have been developed and their effect on magneto-strain and stress-strain characteristics have been investigated [9,34].…”

“…Recent efforts in miniaturization of MSM actuators follow a top-down approach by thinning bulk single crystals to foil specimens [2,9,10]. An alternative is MSMA films that are fabricated in a bottom-up manner by film deposition [11][12][13][14].…”

A novel foil actuator using the magnetic shape memory effect

“…So far, however, no MSM microactuator based on an epitaxial thin film has been demonstrated. An alternative approach is ferromagnetic shape memory foils, which are fabricated by thinning of bulk single crystals showing ferromagnetic shape memory behavior [8][9][10]. In this case, the technological challenges are related to the minimization of surface defects created during foil fabrication.…”