Researchers at the University of Gothenburg announced that they have developed a family of light-driven microgears at the micrometer scale. This gear set is small enough to fit inside a human hair and offers exciting potential for future micro motors.
Although traditional gears are used in many technologies, the drive systems required to move them at micro sizes have long posed challenges. Previously, the drive was weak, and the gear movement was limited to sizes of 0.1 millimeters. These issues, explained as “light-driven gears: entering a new era,” have been overcome by researchers’ approach of abandoning mechanical connections and directly moving gears with laser light.
By using special optical metamaterial structures, micro machines capable of directing light at nanometer scales were produced. The gears produced are only a few tens of micrometers in diameter and can be moved using laser light. Speed control can be achieved through light intensity, and the direction of the gears can also be changed by altering the polarization of the light. Lead author Gan Wang states that this new approach brings a completely different way of thinking: “We have built systems that can move a light-driven gear set. Additionally, these gears can convert rotation into linear motion, perform periodic movements, and direct light with microscopic mirrors.”
According to Wang, the fact that laser light does not require physical contact and can be easily controlled allows for integration into much more complex micro systems. These types of machines hold broad potential for micro systems: by controlling mechanical structures with light, we can surpass size limits.
Developed to be thinner than a human hair, these micro motors are so small that they can fit inside a human hair. Wang emphasizes that this technology has great potential for medical applications. In the future, these motors could process cell-sized particles and be integrated into chip-on-lab systems inside the human body. A gear wheel can be as small as 16-20 micrometers, comparable to the sizes of human cells. Wang envisions that these micro motors could be used in medicine as pumps regulating flows within the human body, functioning as opening and closing valves.
One of the most significant advantages of this technology is the ability to achieve very small sizes, enabling the seamless integration of light-driven motors into micro systems with high performance. This will allow the design of more efficient, smaller, and more complex machines in the future. In fields such as miniature robotics, microrobotic surgery, and biotechnological applications, it could lead to exciting developments in medicine and engineering.
