What lies beneath: Mapping hidden nanostructures

The ability to diagnose and predict the properties of materials is vital, particularly in the expanding field of nanotechnology. Electron and atom-probe microscopy can categorize atoms in thin sheets of material, and in small areas of thicker samples, but it has proven far more difficult to map the constituents of nanostructures inside large, thick objects.  X-rays—the most common imaging tool for hard biological materials such as bones—have a limited focal-spot size, so they cannot focus on nanoscale objects.