Water striders, insects that walk on the surface of the water, may never set foot on land in their lives, and yet they’re not swimmers. Over the past million or so years, this insect—sometimes called a water skater—has optimized its use of surface tension to balance its 0.01-gram body on lakes, ponds, and even oceans.

The first water striding robot, with an appearance and design closely resembling its insect counterpart, doesn’t ever break the surface tension of the water, and is highly maneuverable.

Song and Sitti’s small robot is different from other floating robots in that its small mass and long legs enable it to utilize the surface tension force to stay afloat. In contrast, macroscale bodies must rely on buoyancy, which is based on their large volumes