Soft elastic materials that buckle in a vacuum can generate robot motions.

George Whitesides at Harvard University in Cambridge, Massachusetts, and his colleagues built soft actuators out of squishy cubes containing air pockets. They attached rigid components such as grippers or legs to the cubes and sucked the air out of the pockets using a vacuum. This caused the cubes to collapse, driving the motion of the attached robot parts. When the vacuum was removed, the cubes returned to their original shape. By repeatedly changing the applied pressure, the team made robots that could walk or grab objects (pictured).

The buckling actuators can also be stacked to allow for more-complex motions, the authors report.

Adv. Mater. (2015)