MIT researchers have ironed out the bugs in their latest iteration of an insect-like robotic drone, creating a more agile and resilient model that can fly longer, faster and survive impacts that would have squashed its predecessor.
Weighing about the same as a bumblebee, the microrobot is part of an ambitious effort to develop swarms capable of taking on the delicate, life-sustaining work of pollination like bees do, offering a high-tech solution to an ecological threat rooted in the natural world.
Over the past several years, MIT engineers have significantly enhanced the drone’s soft actuators, the artificial muscles that power its flight. These thin, rubber-like cylinders, coated in carbon nanotubes, elongate and contract when electrically charged, causing the wings to flutter at an astonishing rate, about 500 times per second, The result is a staggering 100-fold increase in flight time, approximately 17 minutes total.
Kevin Chen, an associate professor in the Department of Electrical Engineering and Computer Science (EECS), and head of the Soft and Micro Robotics Laboratory within the Research Laboratory of Electronics. said the focus now is on longer flight times and improving the precision of the robots so they can land and take off from the center of a flower. While the drone still needs to be linked to a power source, the hope is to be able to install within the next three to five years tiny batteries and sensors on them so they can fly and navigate outside the lab, Mr. Chen said. The drones have enough free space to accommodate an internal power source.
“This opens up a lot of opportunity in the future for us to transition to putting power electronics on the microrobot. People tend to think that soft robots are not as capable as rigid robots. We demonstrate that this robot, weighing less than a gram, flies for the longest time with the smallest error during a hovering flight. The take-home message is that soft robots can exceed the performance of rigid robots,” Mr. Chen said.
“Compared to the old robot, we can now generate control torque three times larger than before, which is why we can do very sophisticated and very accurate path-finding flights,” Mr. Chen said. “At the end of the day, we’ve shown flight that is 100 times longer than anyone else in the field has been able to do, so this is an extremely exciting result,” he said. “This new robot platform is a major result from our group and leads to many exciting directions.”
While there may be other practical applications for the drones, such as inspecting hard to reach areas, the devices could potentially become a critical tool for maintaining, and even increasing, food production.
According to the Center for Biological Diversity, the numbers of pollinators, from butterflies to bees to even birds, have collectively declined over the past two decades, attributed primarily to pesticide use and urban expansion. More than half of North America’s 4,000 native bee species are in decline, with one in four species at risk of extension.
And according to the United States Department of Agriculture, “Beehives are often important elements of urban gardens due to the pollination services they provide. They’re also big business. Honeybees pollinate $15 billion worth of crops in the United States each year, including more than 130 types of fruits, nuts, and vegetables. Honeybees also produce honey, worth about $3.2 million in 2017 according to USDA-National Agricultural Statistics Service (NASS).”
Mr. Chen co-authored a paper on his team’s research and development. The team includes Suhan Kim and Yi-Hsuan Hsiao, EECS graduate students, Zhijian Ren, EECS graduate student, and summer visiting student Jiashu Huang. Their paper was published in Science Robotics.
