Tiny Roach-Inspired Robot Withstands 1 Million Times Its Own Weight

A team of roboticists from UC Berkeley developed a practically squash-proof robot inspired by the cockroach's ability to squeeze through the tightest of spaces, a press statement reveals.

Nature-inspired innovations in robotics are bringing us synchronized swarms of robot fish, and drones with flapping dragonfly-like wings.

Now, a team of UC Berkeley engineers developed a tiny, critter-like robot that zips around with impressive speed, and could eventually be used in emergency situations to detect toxic gases and other substances.

A durable, critter-like robot

The so-far unnamed soft robot moves at speeds of 20 body lengths per second, which is almost as fast as a real-like cockroach.

Weighing at between 20-65 milligrams (several prototypes have been developed), it can impressively withstand loads of about 60 kilograms without breaking — which is approximately one million times its own weight.

"Most of the robots at this particular small scale are very fragile. If you step on them, you pretty much destroy the robot," said Liwei Lin, a professor of mechanical engineering at UC Berkeley. "We found that if we put weight on our robot, it still more or less functions."

The UC Berkeley robot's simple design and lack of intricate parts are responsible for its ability to be squashed without breaking — as demonstrated in the video below. It's made out of a thin sheet of polyvinylidene difluoride (PVDF), a material that expands and contracts when a small alternating current is applied.

A front leg and an elastic polymer layer enable the robot to zip forward at a surprising speed — the fastest 10 mm prototype could propel itself forward at 20 centimeters per second when 200 V were applied at 850 Hz.

Roaches inspire the rescue robots of the future

Cockroaches are famously resilient insects. Though the belief that they would survive a nuclear apocalypse might be a little exaggerated, they do show a high level of resilience against certain types of radiation.

So it's no surprise that roboticists have turned to the cockroach for inspiration. Harvard engineers, for example, also recently built a dexterous roach-inspired robot that travels at 14 body lengths per second.

While the UC Berkeley robot currently has to be tethered to an electricity source, the researchers are working on adding a light battery to allow it to autonomously reach hard-to-get-to places with its squashable durability, meaning it could one day be utilized to aid rescue workers.

"For example, if an earthquake happens, it’s very hard for the big machines, or the big dogs, to find life underneath debris, so that’s why we need a small-sized robot that is agile and robust," said Yichuan Wu, first author of a paper detailing the work on the robot.

Aside from a tiny battery, the team also wants to add a gas sensor, which would allow it to squeeze into tight spaces and detect any deadly gas leaks that could pose a risk to rescue teams. 

The design would certainly expand the ability of robots to help in emergency situations. At the Florida condo collapse site, for example, throwable robots have been used to search the rubble for survivors.

The roach-inspired robot's size would give it an advantage in such situations, though the question remains as to how much its resilience would be reduced by adding extra functionality via gas sensors and other pieces of equipment.