The best robots are those that are inspired by nature. Engineers have created a tiny, crawling robot based on the humblecockroach. It is almost as fast and as squashable as its biological counterpart.The soft robot, which is about the same size as a postal stamp, can move at 20 body lengths per seconds and can withstand stress up to a million times its weight.The bot weighs in at less than one tenth of an ounce, and can stand on a human foot for up to 60 kilograms. It just picks up itself and continues on.Liwei Lin, a mechanical engineer at the University of California, Berkeley, says that robots on this scale are often very fragile. "If you step on them you pretty much destroy their robot.""We discovered that our robot can still perform more or less if we add weight to it."The robot's strength is partly due to its simplicity. It is made of a thin layer of polyvinylidene dimfluoride (PVDF) which is a piezoelectric material. This allows it to expand and contract with the use of small alternating currents.This expansion and contraction is what gives the roachbot its ability to move. The scientists added a front leg and a layer of elastic polymer to the sheet, which allows it bend in a way that propels the animal forward.To alter the speed of their designs, the team tried out different lengths of robot (ranging from 10 to 30mm). They also experimented with voltage and frequency of the electric current. A 10 mm robot could run at 20 cm per second at its fastest when 200 V was applied at 850 Hz.The robot can climb up gentle inclines and speed through small tubes. It can also carry loads up six times its weight, as shown by attaching a peanut to the top.The bot is currently wired to an electricity source. However, a future version of the bot could be powered using a small battery.Although it is fun to see clever designs like these, they can also have useful applications. Investigating disaster sites that are unstable and dangerous is one of the many ways tiny bots can help.Yichuan Wu, a mechanical engineer at the University of Electronic Science and Technology of China, said that an earthquake can make it very difficult for large machines or big dogs to find life under debris.The team is currently looking at ways to add a gas sensor to their original design. This would allow the bot to enter very tight spaces and detect any gas leaks that could pose a threat to human life.This is just one of many improvements that engineers want to make to the soft robot. The engineers also want to find a way to make it avoid obstacles while exploring the world around.We've seen the boundaries between biology and robots blurring in recent years, with tiny machines capable of traversing living organisms. These capabilities are only the beginning.The researchers conclude in their paper that the insect-scale robot proposed by them will allow for the development of robust and fast robots for practical purposes.Science Robotics published the research.
