A gear in microscale with a metastructure that reacts to light. (Gan Wang via SWNS)
By Dean Murray
A mind-bogglingly small new motor can fit inside a strand of hair.
Its cell-sized gears are powered by light and could be used as pumps inside the human body.
Researchers at the University of Gothenburg say making the gears on a micrometer scale paves the way for the smallest on-chip motors in history.
(Gan Wang via SWNS)
A University of Gothenburg statement said: “Gears are everywhere – from clocks and cars to robots and wind turbines. For more than 30 years, researchers have been trying to create even smaller gears in order to construct micro-engines. But progress stalled at 0.1 millimeters, as it was not possible to build the drive trains needed to make them move any smaller.”
The researchers have broken through this barrier by ditching traditional mechanical drive trains and instead using laser light to set the gears in motion directly.
In their new study, the researchers show that microscopic machines can be driven by optical metamaterials – small, patterned structures that can capture and control light on a nanoscale.
(Gan Wang via SWNS)
Using traditional lithography, gears with an optical metamaterial are manufactured with silicone directly on a microchip, with the gear having a diameter of a few tens of micrometers.
By shining a laser on the metamaterial, the researchers can make the gear wheel spin. The intensity of the laser light controls the speed, and it is also possible to change the direction of the gear wheel by changing the polarization of the light. The researchers are thus close to creating micromotors.
(Gan Wang via SWNS)
“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,” says the study’s first author, Gan Wang, a researcher in soft matter physics at the University of Gothenburg.
With these advances, researchers are beginning to imagine micro- and nanomachines that can control light, manipulate small particles or be integrated into future lab-on-a-chip systems.
(Gan Wang via SWNS)
The University of Gothenburg statement said: “A gear wheel can be as small as 16–20 micrometers, and there are human cells of that size.”
Medicine is a field that is within reach, believes Gan Wang.
Gan Wang said: “We can use the new micromotors as pumps inside the human body, for example to regulate various flows. I am also looking at how they function as valves that open and close.”