  Shape transformation, a key mechanism for organismal survival and adaptation,
has gained importance across fields as diverse as electronics and medicine.
However, designing and controlling microscale shape-shifting materials remains
a fundamental challenge in various actuation modalities. Here, we introduce
SonoTransformer, an acoustically activated micromachine that delivers ultrafast
transformability using preprogrammed soft hinges. These hinges concentrate
energy through intensified oscillation and provide the necessary torque for
transformation. We have created new machine designs to predetermine the folding
state, enabling tailoring and milliseconds transformation. Additionally, we
have shown selective transformation by adjusting acoustic power, realizing high
degrees of control and functional versatility. Our findings open new research
avenues in acoustics, physics, and soft matter, offering new design paradigms
and development opportunities in robotics, metamaterials, adaptive optics, and
microtechnology.
