Miniature flying robots capable of flipping could pollinate crops in advanced agricultural farms.

In the new design, each of the four units features a single flapping wing extending outward from the robot’s center, which stabilizes the wings and enhances their lift forces. The researchers have also refined the connection between the wings and the actuators, or artificial muscles, responsible for their flapping motion. In earlier models, the actuators were prone to buckling when reaching the extremely high frequencies necessary for flight, which compromised the power and efficiency of the robot. The introduction of a new, longer wing hinge has lessened the mechanical strain on the actuators, enabling them to exert more force. This improvement allows the robots to fly faster, longer, and along more precise paths. The robots can accurately track a trajectory capable of spelling M-I-T.

Weighing less than a paper clip, the new robotic insect can hover for over 1,000 seconds—almost 17 minutes—without any loss of flight precision.

“When my student Yi-Hsuan Hsiao was carrying out that flight, he remarked that it felt like the slowest 1,000 seconds of his life. The experiment was incredibly nerve-racking,” says Chen. The new robot has also achieved an average speed of 35 centimeters per second, marking the fastest flight reported by researchers to date, and is capable of performing body rolls and double flips. It can even precisely trace a trajectory that spells M-I-T.

“At the end of the day, we’ve demonstrated flight that is 100 times longer than what has been achieved by anyone else in the field, making this an extremely exciting result,” Chen states.

Moving forward, he and his team plan to explore how far they can advance this new design, aiming for flight durations exceeding 10,000 seconds. They also intend to enhance the precision of the robots, allowing for takeoff and landing in the center of a flower. Ultimately, the researchers aspire to integrate small batteries and sensors so the robots could operate and navigate beyond laboratory settings. The design has sufficient space for these electronics, as they have reduced the number of wings by half.

Although the bots still do not replicate the fine-tuned behavior of a real bee, Chen expresses optimism. “With the improved lifespan and precision of this robot, we are drawing closer to some very exciting applications, such as assisted pollination.”