After a disaster, robots can find survivors in places where human rescuers can't safely go—at least in theory. But most rescue robots still can't easily navigate through rubble; the most advanced robots in the world still have trouble walking on flat ground without falling down.
A new robot takes a different approach, inspired by one of the animals with a reputation as most likely to survive the apocalypse: the cockroach. The creepier features of a roach—like their ability to squeeze through the tiniest of cracks, or pop up, seemingly indestructible, after someone steps on them—also make them perfect models for rescue robots.
"While we all have had experiences with cockroaches intruding everywhere, we were amazed by the extent of their ability to traverse horizontal crevices smaller than a quarter of their height in less than a second," says researcher Kaushik Jayaram, who led a study of American cockroaches at UC Berkeley and the design of the robo-roach.
Normally, roaches are about a half an inch tall. But inside the tiny obstacle course that the researchers designed, roaches proved that they could fit through a space the height of two stacked pennies. Even more surprising, they could keep moving at top speeds—about 20 body lengths a second, or at human scale, about 70 miles an hour—even when their legs and feet are splayed out to the side.
The new robot, called CRAM, uses a similar design to flatten itself and run through cracks. It's something that other robots can't do; robots that are good at running tend to be stiff and unbendable, and soft robots tend to be slow. "We simply do not have robots today that are capable of both running on rough, uneven terrain and [fitting] into the crevices in the rubble by deforming their bodies and/or reorganizing their legs," says Jayaram.
In an earthquake or building collapse, a team of the robotic roaches could look for victims. "Once CRAM is more developed, we envision the first responders equipping such robots with sensors like a camera, heat detector, etc., and let loose a swarm of them in a disaster zone," he says. "Ideally, these robots will scurry along, enter tight spaces within collapsed structures and attempt to find signs of life and save valuable exploration time."
The robots would communicate with each other and with first responders, potentially mapping out the area and the best routes to enter while they look for survivors. Later, if victims are still trapped, the robots could carry in water, food, and phones or radios.
The researchers plan to make the robot faster, and add more sensors, before it's ready for use. They're also interested in other applications. On a smaller scale, the same type of robots could be used to assist with surgeries. They might also help monitor chemical spills or radiation in places where it isn't safe for humans to crawl. "A swarm of them could also be potentially used for environmental monitoring and assist with conservation efforts," says Jayaram.
All thanks to the roach. "We feel strongly that cockroaches are one of nature’s most revolting animals," says Jayaram. "But they can teach us important design principles."