I’ve often thought about starting a vegetable garden in my backyard. It would be so relaxing to spend my summer afternoons in a floppy straw hat and on-trend denim overalls, tending to my zucchini and tomato plants. I can only imagine how delicious and satisfying meals would be knowing that my hard work brought those vegetables to my table. I suppose the only thing stopping me from living out this agricultural fantasy is my lack of a green thumb…and my tiny yard…and the colony of hungry rabbits that lives beneath my deck…and the growing absence of bees. Well, maybe science can help with that last obstacle.
Researchers at MIT are working to improve artificial pollination through the development of robotic insects. If perfected, this type of high-tech pollination could allow farmers to grow their crops within multilevel warehouses and increase harvests. While bee-inspired robots are nothing new, the researchers have upgraded previous prototypes to produce tiny, aerial robots that are more agile and durable than prior versions. The team claims that these redesigned robots:
- Can hover for approximately 1,000 seconds, 100 times longer than previous models
- Weigh less than a paperclip
- Offer increased speeds over other aerial robots
- Are able to carry tiny batteries or sensors
- Can perform complex aerial maneuvers like double flips
According to the researchers, previous iterations of these insect robots were comprised of four identical units, each with two wings, combined into a rectangular device. The latest design, however, is half the size, with each of the four identical units featuring one flapping wing pointing away from the robot’s center. Additionally, the MIT team created more complex transmissions that connect the wings to the actuators that flap them, thereby reducing the mechanical strain that hindered previous versions.
The team recently published their findings in Science Robotics. In the paper, titled “Acrobatics at the insect scale: A durable, precise, and agile micro–aerial robot,” the researchers outline the many advantages of flapping-wing propulsion over engineered materials and microscale structures in subgram micro–aerial vehicles (MAVs). In comparison to agile and precise insects that can evade predators, recover from wind gusts, or land on moving objects, MAVs are limited to hovering for less than 10 seconds or following simple trajectories at slow speeds.
In an excerpt from the abstract, the researchers write: “Here, we developed a 750-milligram flapping-wing MAV that demonstrated substantially improved lifespan, speed, accuracy, and agility. With transmission and hinge designs that reduced off-axis torsional stress and deformation, the robot achieved a 1000-second hovering flight, two orders of magnitude longer than existing subgram MAVs. This robot also performed complex flight trajectories with under 1-centimeter root mean square error and more than 30 centimeters per second average speed. With a lift-to-weight ratio of 2.2 and a maximum ascending speed of 100 centimeters per second, this robot demonstrated double body flips at a rotational rate exceeding that of the fastest aerial insects and larger MAVs. These results highlight insect-like flight endurance, precision, and agility in an at-scale MAV, opening opportunities for future research on sensing and power autonomy.”
In a recent quote, Kevin Chen, an associate professor in the Department of Electrical Engineering and Computer Science (EECS), head of the Soft and Micro Robotics Laboratory within the Research Laboratory of Electronics (RLE), said, “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.”