The Chinese and American scientists have engineered a small cockroach-inspired soft robot that can move nimbly and withstand the weight of an adult footstep.

The study published on Wednesday in the journal Science Robotics described the one-legged, blade-shaped robot driven by an alternating current.

The researchers from Tsinghua University, Beihang University and the UC Berkeley designed the robot after they observed cockroaches being squished, thus getting a sense of how those sneaky insects manage to squeeze through tight cracks and withstand heavy loads.

A 10-millimeter-long prototype robot moves with a cockroach-like bouncing gait at a speed of 20 body lengths per second, according to the study.

The robot is made of flexible materials that can generate an electrical charge in response to outside forces. Its relatively fast locomotion and robustness are attributed to the curved piezoelectric structure with large amplitude vibration, which renders an oscillatory shape changes during movement similar to many running animals.

The researchers put a series of weights and objects on it and timed how quickly it moved along a ruler. They found the robot is able to carry loads up to six times its own weight and climb the 7.5-degree slope at a speed of seven body lengths per second. Also, it can withstand the weight of an adult human foot, approximately one million times heavier than the robot itself.

The robot is unique since it has flexible but strong exoskeleton. Most other robots are made of rigid parts and move clumsily as a result.

The researchers also created a two-legged prototype that could emulate features of galloping-like motions.

They expected to develop the robot into real-world applications like environmental exploration, inspection and disaster relief, according to the researchers.

Small, durable robots like these could be advantageous in search and rescue missions, squeezing and squishing into places where dogs or humans cannot fit, or where it may be too dangerous for them to go, according to the study.

"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 the paper, who completed the work as a graduate student in mechanical engineering at UC Berkeley through the Tsinghua-Berkeley Shenzhen Institute partnership Enditem