  Shape-programmable soft materials that exhibit integrated multifunctional
shape manipulations, including reprogrammable, untethered, fast, and reversible
shape transformation and locking, are highly desirable for a plethora of
applications, including soft robotics, morphing structures, and biomedical
devices. Despite recent progress, it remains challenging to achieve multiple
shape manipulations in one material system. Here, we report a novel magnetic
shape memory polymer composite to achieve this. The composite consists of two
types of magnetic particles in an amorphous shape memory polymer matrix. The
matrix softens via magnetic inductive heating of low-coercivity particles, and
high-remanence particles with reprogrammable magnetization profiles drive the
rapid and reversible shape change under actuation magnetic fields. Once cooled,
the actuated shape can be locked. Additionally, varying the particle loadings
for heating enables sequential actuation. The integrated multifunctional shape
manipulations are further exploited for applications including soft magnetic
grippers with large grabbing force, sequential logic for computing, and
reconfigurable antennas.
  Keyword: shape memory polymers, soft active materials, magnetic soft
material, soft robotics, soft material computing
