If there’s one thing the world doesn’t need, it might be more cockroaches.
That’s not the case, according to a collaborative group of boffins from China and the University of California at Berkeley, who have joined forces to create an almost indestructible, super-fast robot the size of a cockroach.
While some of our readers may now be standing, raising their fists to the sky and shouting “WHY? WHY? ”In the long term, insect scale robots have potentially many extremely useful applications.
The China / Berkeley team listed “environmental exploration, structural inspection, information reconnaissance and disaster relief” as possible uses, all of which seem useful and obvious. With the possible exception of “information recognition”, which sounds extremely frightening.
But small insect-scale robots present unique design challenges compared to their bigger, bulkier, industrial and police cousins.
“Soft insect-scale robots are known to be easily damaged, exhibit poor locomotion control, or move slowly due to the nature of their small structures.” the team paper in the review Scientific robotics points out.
“These robots are made of rigid or partially rigid parts, which results in low robustness and low adaptability to changes in shape and / or external disturbances,” adds the document.
They are therefore easily damaged and cannot bend or twist to cope with imperfections in the terrain. Which obviously isn’t good if you’re trying to build a robot that can do anything useful.
The researchers also tried to build tiny robots with soft, flexible bodies activated by heat, light, magnetism or even humidity. But these generally have “slow responses, while others require bulky configurations to generate the external power sources such as magnetic fields.”
While such robots may have applications under certain conditions, obviously light, heat, or humidity will not always be available, and there seems to be no point in building an insect scale robot if it does. must be accompanied by a large and heavy set of external magnets.
The China / UC Berkeley team therefore tried a new approach and built a seemingly simple robot from a sheet of polyvinylidene difluoride (PVDF), a material with piezoelectric qualities that contracts and expands when an alternating current passes through it.
When combined with additional ‘leg’ structures mounted under the roach-bot, this gives it the ability to move using a wave-like motion (see video below).
As the newspaper explains:
Under an alternating current (AC) drive power close to the resonant frequency (850 Hz) of the structure, a 10 mm long (0.024 g) robot prototype achieved a relative speed of 20 BL / s [body lengths per second] – fastest among published insect scale soft ground robot reports.
So he can move and move quickly. So far so roach. But the jerky speed isn’t the only advantage of PVDF. It’s also tough and deformable, which means that despite being less than a tenth of a gram, the team was able to submit another 0.06g prototype to “The total weight of an adult human” of 59.5 kg (131 lbs) – roughly a million times its own mass – and it was still able to buzz in a weird way afterwards.
This allows the UC Berkeley cockroach robot to mimic one of the cockroach’s most infuriating qualities – it’s incredibly difficult to get rid of.
“Most robots on this small scale are very fragile,” Liwei Lin, mechanical engineer and UC Berkeley project contributor, said to Berkeley News. “If you step on it, you pretty much destroy the robot. We have found that if we put weight on our robot, it always works more or less.”
So what’s the future of a little robot that behaves like a cockroach and even looks a bit like it? Well, the prototype currently relies on external power sources, so the team is hoping to build an improved version powered by an on-board battery.
Once that’s sorted, the sky – or in this case, the ground – is the limit. As shown in the video, the roach-bot can go up and down slopes, through pipes and can carry six times its own weight. Its light weight and simplicity mean it would likely be cheap enough to be disposable.
One application would be exploring disaster sites, looking for survivors, dangerous areas and gas leaks using an on-board gas sensor. While many roach bots would get stuck crawling a site such as the recent The collapse of a Surfside condominium in Miami, if enough were freed, some could find their way through the rubble to make useful contributions to the rescue effort.
Of course, once they are properly developed, they will also inevitably be used to spy on people, sabotage cables, and prank those who dislike cockroaches. Which is, at last count, just about everyone.
So thanks for that, boffins. ®