Robotic cockroach explores underwater


IN nature, cockroaches can survive underwater for up to 30 minutes. Now, a robotic cockroach can do even better. Harvard’s Ambulator Microrobot, known as HAMR, can walk on land, swim on the surface of water, and walk underwater for as long as necessary, opening up new environments for this little bot to explore.

This next generation HAMR uses multifunctional foot pads that rely on surface tension and surface tension induced buoyancy when HAMR needs to swim but can also apply a voltage to break the water surface when HAMR needs to sink. This process is called electrowetting,
which is the reduction of the contact angle between a material and the water surface under an applied voltage. This change of contact angle makes it easier for objects to break the water surface.

“This research demonstrates that microrobotics can leverage small-scale physics — in this
case surface tension — to perform functions and capabilities that are challenging for larger robots,” said Kevin Chen, a postdoctoral fellow at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and first author of the paper.

The most recent research is published in the journal Nature Communications.