Japanese scientists have created a molecular device resembling a ‘scissor’ that can be used to control genes, proteins and other molecules in the body. This scissor can be opened and closed with the effect of light. This device, created by Takuzo Aida and his colleagues at the University of Tokyo, consists of a pivot, handles and blades which make it look like a scissor and it is just 3 nanometers long, making it the world’s smallest scissor. Rings of carbon and hydrogen known as phenyl groups have been used to make the blades and the pivot is a molecule called chiral ferrocene, which sandwiches a round iron atom between two carbon plates which can rotate freely around the iron atom. The handles are organic chemical structures called phenylene groups which are tethered together with azobenzene, a molecule that reacts to light. Shining visible light on the scissors makes the azobenzene expand and drive the handles apart, closing the blades. Shining ultraviolet rays does the opposite and opens up the blade. The device can be used as a pincer to firmly grasp molecules and manipulate them by twisting them back and forth. Takuzo Aida said: This work is the first example where a molecular machine mechanically manipulates other molecules by light .This work is an important step for the future development of molecular robotics. With the success met in this device, the researchers are now making a larger scissor which can be remotely manipulated and can be operated using near-infrared lights,that can find use in the body by reaching deep parts of the body. Source.