If you want to look at the world's smallest microscope, using your own eyes may not be enough: you would need another microscope to do that. This microscopic microscope has been developed by Neol McDonald and his students at the Cornell University in the US, and is a scaled-down version of the Scanning Tunneling Microscope - which earned Heinrich Rohner and Gerd Binning a Nobel prize in 1986. Built on a silicon chip, it is just 200 micrometers wide.