New York: X-rays have taken pictures of broken bones for decades, but scientists have now refined them to capture images of ultra-small particles in nano and bio-materials, including cellular nuclei.

This development will facilitate understanding of how materials behave electrically, magnetically and under thermal and mechanical stress. Besides, its applicability to biology and biomedicine will also contribute to our understanding of disease and its eradication, healing after injury, cancer and cell death.

Ideally, X-rays are suited for nanoscale imaging, because they can penetrate the interior of an object, but their lens acts as a limitation. Scientists, however, overcame the problem by doing away with the lens at Argonne National Lab. Researchers from Argonne and the universities of California, Melbourne and La Trobe developed a method to examine internal and buried structures in micrometer-sized samples.

Ian McNulty, Argonne author of the publication appearing in Physical Review Letters, said: "Instead (of a lens), a computer uses sophisticated algorithms to reconstruct the image. We expect this technique will enhance our understanding of many problems in materials and biological research."

The technique can be extended beyond the current resolution of about 20 nanometers to image the internal structure of micrometer-sized samples at finer resolution, reaching deep into the nanometer scale.

Electron microscopes can image structural details on nanometer scale, but once the sample reaches sizes of a few micrometers and larger, the usefulness of these instruments to probe its internal structure is limited.

Another team developed a powerful new extension of the lens-less imaging technique for high-resolution imaging. If the nucleus or other parts of a cell are labelled with protein specific tags, it can be imaged within whole cells at a resolution far greater than that of ordinary microscopes.

Another application of this new method includes nano-engineering, seeking more efficient catalysts for the petrochemical and energy industries and materials with electrically programmable mechanical, thermal and other properties. IANS