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MIT scientists have developed tiny, flying robot insects that are more agile and durable than ever in the hopes of someday using them for pollination. These newly designed robot insects can fly for up to 15 minutes and perform acrobatic maneuvers without breaking.
“The revamped robot is designed to boost flight precision and agility while minimizing the mechanical stress on its artificial wing flexures, which enables faster maneuvers, increased endurance, and a longer lifespan,” the scientists explained in a press release. “The new design also has enough free space that the robot could carry tiny batteries or sensors, which could enable it to fly on its own outside the lab.”
Prior versions of their flying robot insects were made up of four identical units, each with two wings. However, Kevin Chen, an associate professor in the Department of Electrical Engineering and Computer Science (EECS) and the senior author of the study, said “the performance of each individual unit was always better than the assembled robot.”
So they made it smaller and less complicated. Now each of the four identical units has one flapping wing pointing away from the robot’s center, stabilizing the wings and boosting their lift forces. Also, the reduction of the number of wings now makes it possible for the robot insects to carry electronics such as tiny batteries or sensors.
Now their robot insect, which weighs less than a paperclip, can fly for about 1,000 seconds, or more than 100 times longer than their previous models.
“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,” said Chen.
“The amount of flight we demonstrated in this paper is probably longer than the entire amount of flight our field has been able to accumulate with these robotic insects. With the improved lifespan and precision of this robot, we are getting closer to some very exciting applications, like assisted pollination,” Chen added.
The motion of the robot’s wings is driven by artificial muscles. These tiny, soft actuators are made from layers of elastomer sandwiched between two very thin carbon nanotube electrodes and then rolled into a squishy cylinder. The actuators rapidly compress and elongate, generating mechanical force that flaps the wings.
They used a multistep laser-cutting process to precisely fabricate each wing hinge which reduces torsional stress experienced during the flapping-wing motion. Which is important, because as Chen told New Scientist, “If you only have 20 seconds to fly the robot before it dies, then there’s not so much we can tune when we control the robot.”
This new design was then able to reach an average speed of 35 centimeters per second while performing body rolls and double flips. Unfortunately, their robot insects are currently unable to fly untethered – something that the scientists are working to remedy.
“This new robot platform is a major result from our group and leads to many exciting directions. For example, incorporating sensors, batteries, and computing capabilities on this robot will be a central focus in the next three to five years,” Chen said.