Scattering microscope peers into the nanoscale

Science : Traditional microscopes can’t resolve objects smaller than half the wavelength of the light used to illuminate them; electron microscopes get around this by replacing the visible light with electron beams, which have a much shorter wavelength and a much smaller intrinsic blur. However, electrons pass right through thin samples of most living tissue unless it’s been prepared in a radical way—which prevents researchers from viewing living organisms. E. G. van Putten, of MESA+ Institute for Nanotechnology in Twente, the Netherlands, and colleagues etched a gallium phosphide lens with sulfuric acid to produce a frosted surface that scattered light in all directions. They then used a computer to design a light wave that, when passed through and scattered by the lens, would focus to a point. It seems counterintuitive, but the randomization and reconstruction process allowed the researchers to form a sharper image than would otherwise have been possible. They were also able to create an ultrasharp image of the entire sample by rotating the incoming light wave and scanning the focus across the sample. Thus far, they have imaged gold nanoparticles with a resolution as small as 97 nm. With a more powerful light source and some fine-tuning, it should be possible to see details of living tissue samples, including nanoscale processes such as viruses invading cells.