We've all been in this situation. You spot a cockroach and go to get a shoe to squish it, yet it runs and squeezes through an impossibly small crack faster than the blink of an eye, or maybe you are able to get to it and give it a good whack, but it still escapes unharmed. [Editor's note: Some of us foolhardy types go for capture and release, but you get the point.]
Their ability to scramble through small spaces and withstand the force of a shoe or book makes them pretty creepy, but it's those characteristics that researchers say make them the best inspirations for search and rescue robots.
A team of researchers at the University of California, Berkeley have been studying cockroaches and discovering their secrets. It turns out that the bugs can not only fit into crevices that measure one-tenth of an inch, but they can continue to run at top speed -- 5 feet per second, or 50 times their body length per second -- once inside, even though they've flattened their bodies.
"What's impressive about these cockroaches is that they can run as fast through a quarter-inch gap as a half-inch gap, by reorienting their legs completely out to the side," said study leader Kaushik Jayaram, who recently obtained his Ph.D. from UC Berkeley. "They're about half an inch tall when they run freely, but can squish their bodies to one-tenth of an inch—the height of two stacked pennies."
The researchers used high speed cameras to capture the insects dashing through tight spaces and found that since they can't properly use their feet when flattened to run, they instead use the sensory spines on their tibia to push against the floor and move forward.
If that's not already impressive, while the insects are in these tight spaces, they can withstand forces 900 times their body weight without being injured.
Using this information, the team designed a robot called Called CRAM for compressible robot with articulated mechanism that can rapidly fit through cracks and is tough enough to compress without being crushed. The robot version is the size of your palm and splays its legs outward to run when going through tight spaces half its height, just as roaches do. It has a plastic shield similar that acts like the tough, smooth wings covering the back of a cockroach.
"In the event of an earthquake, first responders need to know if an area of rubble is stable and safe, but the challenge is, most robots can't get into rubble," said Robert Full, a professor of integrative biology at UC Berkeley. "But if there are lots of cracks and vents and conduits, you can imagine just throwing a swarm of these robots in to locate survivors and safe entry points for first responders."
The model robot was built using an origami-like production process that is very inexpensive, but they as the researchers move forward and build a version for real-world testing, they believe that the robot can still be manufactured cheaply and could one day be the first line in rescue operations after both natural and man-made disasters, looking for survivors and safe entry points for first responders.
You can see more in the video below.