This is the first insect-scale robot capable of walking on land, moving on the surface of water, controllably sink into water, walk under the water, and eventually transition back onto land.
When a robot weighs 1.6g and is several centimeters long, it faces opportunities and challenges unique to its scale. Leveraging on surface tension, the robot can easily move along the surface of water. On the other hand, it needs to overcome the inhibiting surface tension force when it wants to transition into or come out of water. This is the first centi-metered scaled robot that can freely transition between land, the surface of water, and underwater.