Scientists Build World’s Smallest Wireless Flying Robot Amid Other Tiny Robotic Innovations

The world of robotics is growing at a tremendous pace.

Scientists, researchers, and technology companies are building robots for a wide range of purposes, including building smartphones, stacking items in warehouses, helping around the house, enhancing healthcare, hauling goods, and a lot more.

At the same time, innovators are concerned about the pitfalls of advancing robotics—including trailing competitors (a sentiment shared by the United States and Europe), losing jobs, falling prey to cybercriminals, and other security issues.

Yet, the robotics industry powers through, and the current popular avenue for innovation is tiny robots.

From creating the smallest, lightest solar-powered drone to building safe systems that enable users to control thousands of robots, drones, driverless cars, and more simultaneously.

In the latest bout of innovation, engineers from the University of California, Berkeley (UC Berkeley) have created the world’s smallest wireless flying robot. The engineers took inspiration from insects—particularly bumblebees—while designing this miniature robot.

“Bees exhibit remarkable aeronautical abilities, such as navigation, hovering and pollination, that artificial flying robots of similar scale fail to do,” said Liwei Lin, Distinguished Professor of Mechanical Engineering at UC Berkeley, who is the senior author of a new paper describing the robot.

The robots measure less than a centimeter in diameter and weighs only 21 milligrams—traits that make it the world’s smallest wireless robot capable of controlled flight. In comparison, the next smallest robot with similar flight capabilities is 2.8 cm in diameter—almost three times the UC Berkely robot’s size.


As per the engineers, the robot can hover, change trajectory, and even hit small targets.

“This flying robot can be wirelessly controlled to approach and hit a designated target, mimicking the mechanism of pollination as a bee collects nectar and flies away,” Lin added.

Furthermore, the robot breaks one more barrier that ordinarily stands in the way of such innovation—its power source. Usually, robots are fitted with batteries and electronics for flight control, elements that make producing small, lightweight devices challenging. Here, Lin and the UC Berkeley team leverage an external magnetic field to power and control the device.

The UC Berkely robot is shaped like a small propeller. It includes two small magnets that work in tandem to attract and repel each other, making the propeller spin and generate enough lift to make it fly. Flight plans are controlled by modulating the strength of the magnetic field.


However, currently, the robot is only capable of passive flights—it doesn’t possess on-board sensors allowing it to detect its current position or trajectory and can’t adjust movements in real-time. This means that it can be programmed to follow preset, precise flight paths, but unexpected shifts in the environment, such as sudden gusts of wind, could knock it off its path.

“In the future, we will try to add active control, which would allow us to change the robot’s attitude and position in real time,” said Wei Yue, co-first author of the study and a graduate student in the Liwei Lin lab.

Yet, such robots offer great promise.

“Tiny flying robots are useful for exploring small cavities and other complicated environments,” said study co-first author Fanping Sui, who recently completed a Ph.D. in engineering at UC Berkeley. “This could be used for artificial pollination or inspecting small spaces, like the inside of a pipe.” 


This robot builds on a previous one created by Lin’s team in 2019—a cockroach-inspired robot that can scurry across the floor at nearly the speed of a darting cockroach and survive being stepped on by a human. It was built using a layered material that bends and straightens when AC voltage is applied.

“Most of the robots at this particular small scale are very fragile. If you step on them, you pretty much destroy the robot,” said Liwei Lin, senior author of the study. “We found that if we put weight on our robot, it still more or less functions.”

Such robots can be helpful in search and rescue missions where dogs or humans can’t go.

“For example, if an earthquake happens, it’s very hard for the big machines, or the big dogs, to find life underneath debris, so that’s why we need a small-sized robot that is agile and robust,” said Yichuan Wu, first author of the paper, who completed the work as a graduate student in mechanical engineering at UC Berkeley.


Do you think the development of such tiny robots will lead the way for future innovation in robotics?

Let us know in the comments below!