For the smallest motors, nothing gets the gears turning like laser beams. After years of trying to make gears more compact, scientists have now created ones on a micrometer scale that run entirely on light.
A new study published in Nature Communications explains how light-powered gears could usher in the tiniest of technology, motors so small that they can fit inside a stand of hair. At this size, micromotors planted on chip devices could pave the way for unprecedented medical treatments.
Micromotors and Nanomotors
In many ways, gears make the world run smoothly. They act as essential components in machines big and small, from managing the speed of wind turbines to turning the hands of a watch. But looking to the future, the most pivotal innovations in technology will likely come as gears become progressively smaller.
Micromotors — and even smaller nanomotors — are poised to make an impact in various fields, from robotics to optical systems. But perhaps their most instrumental role could be in microfluidics, which involves the development of devices that can manipulate small amounts of liquid (at scales of anywhere between 1 to 1000 micrometers).
Microfluidics is especially relevant in medical technology, already being used for tasks like detecting diseases and developing medicines. It has even spawned multiple iterations of the organ-on-a-chip, a device that is allowing scientists to model human organs and tissues.
One of the main hopes for micromotors is that they can be used to help deliver nutrients or drugs throughout the body. They could potentially serve as a support system for lumina, the passages in organs that transport substances, facilitating urination and bloodstream flow.
Read More: The Future of Organ-Chip Technology Is Bright
Powering Gears with Laser Light
For micromotors to work, they need gears that are exceptionally small. Scientists have been working on the miniaturization of gears for more than 30 years, but they’ve consistently had trouble making them smaller than 0.1 millimeters due to difficulties building the drive trains needed to make them move.
However, the researchers involved with the new study have overcome this challenge by turning to laser light rather than mechanical drive trains.
In the study, the researchers demonstrate that microscopic machines can be driven by optical metamaterials, which are small, patterned structures that can capture and control light on a nanoscale. They created gears only a few tens of micrometers in diameter that feature an optical metamaterial and are manufactured with silicon directly on a microchip.
The researchers were then able to make the gear wheels spin by shining a laser on the metamaterial. They say that the speed can be controlled by the intensity of the laser light, while the direction of the gear wheels can be altered by changing the polarization of the light.
"We have built a gear train in which a light-driven gear sets the entire chain in motion. The gears can also convert rotation into linear motion, perform periodic movements, and control microscopic mirrors to deflect light," said first author Gan Wang, a researcher in soft matter physics at the University of Gothenburg, in a statement.
Tiny Machines, Big Impact
Micromotors that can be built on chips and powered by light may revolutionize machinery, since laser light does not require any fixed contact with the machine and is easy to control, according to the researchers.
“This is a fundamentally new way of thinking about mechanics on a microscale. By replacing bulky couplings with light, we can finally overcome the size barrier,” said Wang in the statement.
As they become more commonplace, microscopic machines are sure to make a difference in medicine. And since gear wheels can even be the same size as some human cells — around 16 to 20 micrometers — they may be able to aid our health in ways that have never been achieved at such a small scale.
Read More: Why Flat Cell Imagery Is Set to Revolutionize Microscopy
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- Nature Communications: Microscopic geared metamachines
