The science of small is fascinating, isn’t it? I mean, the things that scientists are able to accomplish in the field of nano technology is astonishing to people like myself, who only have a rudimentary understanding of the science of Physics, Chemistry and Biology. The recent publication in Nature Nanotechnology noted that ICFO researchers have for the first time, demonstrated the ability to use something called ‘near-field optical tweezers’ to trap a nano-size object and then manipulate it in the 3 dimensions of space.
ICREA Professor and leader at ICFO of the Plasmon Nano-Optics research group, Romain Quidant, said, “this technique could revolutionize the field of nanoscience since, for the first time, we have shown that it is possible to trap, 3D manipulate and release a single nano-object without exerting any mechanical contact or other invasive action”.
Let me break things down for you. Let’s say you can imagine an elephant that is trying to get hold of a needle with its gigantic foot? Obviously this would be a remarkable if not impossible feat because of the elephant’s size in comparison to the needle. Now what if you were to imagine that the needle is a single molecule or tiny object about the size of a few nanometres. You, with your standard tools, need to stop it and manipulate it, in order to study it in greater detail.
Before you think I’m calling you an Elephant, I’m not. But, the same problem occurs, because a standard optical microscope is not at all capable of focussing on a single molecule and also, because our standard tweezers are basically not capable of stopping and or manipulating such a small object due to the size of the tweezers compared to the size of the molecule.
The original optical trapping, was invented in Bell Labs back in the 80’s. It demonstrated the capability to trap and manipulate small objects of micrometer size dimensions using laser light. It did this by shining a laser light through a lens, focussing the light in a minuscule spot, thereby creating an attractive force due to the gradient of the light and the intensity of the laser and it then attracted the object and maintained it in the focus of the light. A few years ago, ICFO researchers had demonstrated that by focusing light on a gold nano-structure on a glass surface (which acts as a nano-lens), you were able to trap an object at the locality of the metal, where the light is concentrated. This concept tools were called ‘plasmonic nano-tweezers’
The researchers at ICFO have taken this proof of concept a step further by implementing these ‘plasmonic nano-tweezers’ at the extremity of a mobile optical fibre, which has been nano-engineered with a bowtie looking, gold aperture. By using this approach, they have demonstrated the trapping and 3D displacement of objects as tiny as a few tens of nanometres using extremely small, non-invasive laser intensity. This technique is potentially attractive in the field of medicine, as a tool to further understand the biological mechanisms behind the development of diseases.
Personally, I find this information fascinating, how about you? If you have any sensible comments regarding this story, please leave your comments in the section below.
[Image via: kavliprize]