Scientists have created the tiniest “tweezers” known to date, which can move around objects the size of single molecules with a “bow tie” of light.
“To my knowledge these are the smallest tweezers ever built,” physicist Mathieu Juan, from Sydney’s Macquarie University, told the Australian Broadcasting Corp. “They will allow people to manipulate, scan and move around very small objects such as viruses.”
via Popular Science
I don’t know if the word ‘tweezer’ is right. I think maybe a new word is needed.
It’s the shape of this opening that allows the beam of light to be controlled with such “exquisite precision,” says Juan.
The device is based on a mechanism known as “self-induced back action”, he explains. In essence, this means that optical tweezers are designed to shape themselves to the presence of the object they are picking up.
“In other words the trapped specimen plays an active role in the trapping mechanism,” the authors write.
Where the two triangles of the bow-tie shape meet, a very gentle force is generated, which does not result in any temperature increase that might damage a biological molecule, Juan says.
The researchers report that they used the device to pick up and move around a plastic sphere just 50 nanometres across – a thousandth the width of a human hair.
Over the course of several minutes, they were able to move the trapped sphere over large distances.