Fig. 2: Mechanism study on programming and reprogramming magnetic anisotropies in MRSM films.

a An optical image of NdFeB@PCL MPs. b Schematic and optical images showing reorientation of NdFeB MPs in NdFeB@PCL MPs by an external magnetic field when heated above the melting temperature of PCL. c, d Schematic of two different magnetization patterns in a MRSM strip, their corresponding magnetic flux density distributions, morphed 3D shapes for the actuated MRSM strip under the same actuation magnetic field and the expected 3D shapes resulting from FEA simulation. e–j Schematic of laser programmed magnetization patterns, the corresponding 3D shapes simulated by FEA, and really actuated 3D shapes in the same MRSM strip. The strip is actuated under a magnetic field of 150 mT, which is perpendicular to the strip as indicated by the red arrow. Scale Bars: 5 mm.