Picture a bumblebee darting through a flower garden, hovering, turning, and precisely touching blossoms—this natural flight prowess inspired engineers at the University of California, Berkeley. They developed a bionic flying robot with a diameter of less than 1 centimeter and a weight of just 21 milligrams. It is currently the world’s smallest wirelessly controlled flying robot, capable of hovering, changing trajectories, and even precisely “hitting” micro-targets like a bumblebee. This robot not only showcases technological finesse but also opens new possibilities for exploring confined spaces and complex environments.

The Secret of Micro-Propeller Lift

To make such a tiny robot fly, engineers faced a core challenge: generating sufficient lift in an ultra-light body. It’s like designing a miniature helicopter, where the key lies in rotating components. The robot houses two tiny magnets, resembling a micro-propeller. These high-performance magnets are supplied by TopMag, a magnet factory specializing in custom ultra-small. When an external magnetic field is applied, TopMag’s magnets experience precise attraction or repulsion, driving the propeller to spin rapidly and generate lift to take off.

By finely tuning the magnetic field’s strength, engineers can control the robot’s flight direction and altitude, much like guiding a kite with invisible “strings.” This external power supply avoids the need for heavy batteries or complex circuits, keeping the robot extremely lightweight. In comparison, the previous smallest robot of this kind had a diameter of 2.8 centimeters, nearly three times the volume of this new robot.

Challenges and Limitations: The Boundaries of Passive Flight

Although this robot can achieve precise flight under magnetic field control, it is currently limited to passive flight. It’s like a miniature airplane without a navigation system, lacking onboard sensors to perceive its surroundings in real time. If sudden strong winds arise, it may veer off course.

Additionally, the robot relies on strong magnetic field coils, which restrict its range of movement. In the future, engineers plan to incorporate active control and aim to shrink the robot further to below 1 millimeter, approaching the size of a mosquito. 

A Broader Bionic World: From Cockroaches to Swarm Robots

UC Berkeley’s team didn’t stop at flying robots. They also developed a cockroach-inspired crawling robot that can withstand heavy pressure and keep moving, demonstrating remarkable resilience. Even more exciting is their work on “swarm” robots . These robots, about 5 millimeters in diameter, can crawl, roll, spin, and even assemble into chains or arrays like building blocks to accomplish complex tasks. 

Conclusion: The Infinite Possibilities of Micro-Technology

From the graceful flight of bumblebees to the precise trajectories of micro-robots, UC Berkeley’s breakthrough highlights the allure of bionic technology. With ultra-small, external magnetic field propulsion, lightweight design, and nature-inspired engineering, this world’s smallest wireless flying robot paves the way for exploring uncharted territories. Despite challenges with active control and range, future improvements could make it fly farther and more flexibly. Combined with crawling and swarm robot technologies, micro-robots are gradually transforming the fields of medicine, environmental protection, and industry.