“Something that is one of nature’s most revolting animals can teach us design principles that could some day lead to a robot that could some day save your child in an earthquake,” said Dr. Robert Full and Kaushik Jayaram, lead researchers on the prototype study. American cockroaches are the most common type, and they are known for being generally unpleasant insects. Nonetheless, cockroach exoskeletons are composed of several rigid plates and connective tissue that together allow the pests to be incredibly flexible. Cockroaches can flatten themselves into spaces about one quarter their natural height. And even in crevices and tiny crawlways, cockroaches can still run at 20 body lengths per second. That would be like a human sprinting 70 miles an hour, said Full.
In a test environment, researchers watched cockroaches withstand pressures up to 900 times their body weight without injury. The test roaches were also able to keep moving through spaces that exerted 300 times the cockroaches’ body weight in compression force. So the prototype for a Compressible Robot with Articulated Mechanisms (CRAM) uses the same design principles behind the cockroach’s impressive body structure. It has a flexible exoskeleton with rigid plates, and legs that can splay out and still gain traction when CRAM’s body is squeezed into tight spaces.
At this stage, CRAM’s creators admit that the robot is just a prototype and could do with further improvements. It’s still 20 times larger than the American cockroach, and can only perform one of the eight or nine typical actions that a cockroach might display in tight spaces. Nonetheless, CRAM is on the right track to be a powerful resource in search and rescue efforts. Researchers believe multiple CRAM robots could be deployed in swarms to map out dangerous rubble zones and report back to human search and rescue experts about trapped survivors and safety information that would inform extraction plans and ultimately, save lives.
