Researchers at the Centre for Nano Science and Engineering at the Indian Institute of Science (IISc), Bengaluru, have developed a technique to trap and move tiny objects in the nanoscale using optical “tweezers” employing light. This was partly solved with the development of “plasmonic tweezer” which works on the principle that when a disc of noble metal, like gold, is illuminated with light, it creates an electromagnetic field around the disc. They integrate a silver nanodisc with a microrod made of glass and the combination can be manipulated using laser beams alone. “The optical tweezer holds the plasmonic tweezer and the plasmonic tweezers trap our target nanoparticles, therefore tweezer (plasmonic) in tweezer (optical),” says Souvik Ghosh, first author of the paper. “The intensity required is about 100 times lower that what a regular optical tweezer typically uses to hold an object of similar dimensions,” he explains.

Source: The Hindu September 28, 2019 14:15 UTC