Researchers at Leiden University have developed 3D-printed microscopic robots that swim and navigate obstacles without sensors or electronic brains. This advancement signifies a shift in microrobotics, as these robots rely solely on their physical design and environmental interactions.
The findings were published in the Proceedings of the National Academy of Sciences. The microrobots feature soft, chain-like structures made of flexibly connected segments, each measuring 5 micrometres across. They move at a speed of approximately 7 micrometres per second when an electric field is applied.
The behavior of the robots emerges from their design rather than pre-programmed instructions. Daniela Kraft, leading the research, stated, “We discovered there’s continuous feedback between the shape and motion of the robot: the shape influences how it moves, and its movements in turn alter its shape.” This eliminates the need for microscopic electronics.
When slowed or stopped, the robots wave their tails while the rear segments continue to propel them forward. They also automatically reroute when encountering obstacles and steer away from one another during interactions.
The design draws inspiration from biological creatures such as worms and snakes. Kraft noted, “Until now, microrobots were either small and rigid, or large and flexible.” The creation of adaptive microrobots through physical structure offers new opportunities in biomedical applications, including targeted drug delivery and minimally invasive medical procedures.
The researchers aim to understand the dynamics that give rise to such behavior to enhance microrobot technology and insights into biological microswimmers. Kraft emphasized, “We now need to fully understand how such dynamic and functional behavior emerge.” This knowledge may lead to advancements in both microrobots and the comprehension of biological organisms.
