- Scientists break the world record for the fastest spinning object.
- The new object revolves at 300 billion revolutions per minute.
- It is made of a dumbbell-shaped silica nanoparticle powered by lasers.
Torque sensors enabled the first determination of the gravitational constant and the discovery of Coulomb’s law. In the recent decade, significant efforts have been made to enhance torque detection sensitivity.
Now researchers at Purdue University have achieved remarkable sensitivity in torque sensors at room temperature. They have done this by building the world’s fastest-spinning object.
The object is nothing but a dumbbell-shaped silica nanoparticle powered by lasers. It revolves at 300 billion revolutions per minute, nearly 500,000 times faster than a dentist’s drill.
How Did They Do This?
They levitated a silica nanoparticle in a vacuum using laser light, and then used a second laser with a polarizing plate to test its torque sensitivity.
More specifically, they optically trapped a silica nanoparticle (a nanosphere) in a vacuum chamber using a tightly focused 1,550-nm laser. They then used another 1,020-nm laser to apply an external torque and measure its sensitivity.
While doing so, researchers set a world record for the fastest spinning object. They broke their previous record (set in 2018) of 60 billion revolutions per minute.
The optically trapped 170-nm diameter nanodumbbells were driven to rotate beyond 1 GHz, the highest reported rotation frequency for a nanoparticle to date. Researchers estimate that smaller silica nanodumbbells can sustain rotational frequency beyond 10 GHz.
Courtesy of researchers
In addition to their remarkable rotational speeds, these nanoparticles can measure torque at levels up to 700 times more sensitive than any instrument before.
Such high-speed rotations will be used to analyze material properties and vacuum friction. For example, the torsional vibration of the levitated nanoparticles is observed in the presence of a linearly polarized laser. This could be a crucial step towards detecting the Casimer torque (physical forces arising from a quantized field) and developing and controlling nanoelectronic devices.
Moreover, it will be useful for creating a quantum Cavendish torsion balance, which will eventually help scientists better understand the quantum nature of gravity. Multiple nanoparticles can be levitated together to analyze the self-assembly and nonequilibrium phases.