Microscope shows changes over time

A 3D microscope that shows changes in materials over time is giving a unique insight into microscopic internal structure and chemical composition. The device could lead to advances in a range of areas, such as healthcare, the development of better construction materials, improved oil extraction methods and even the study of fossils.

The X-ray microscope uses 'time delay integration', which enables it to generate better images of larger objects than other devices, meaning microscopic structure can be studied with greater accuracy.

With EPSRC (Engineering and Physical Sciences Research Council) funding, a multi-disciplinary team drawn from six UK universities has been developing and using the microscope, which is similar to the CT scanners used in healthcare but can view things in much greater detail.

X-ray microscopes can produce 3D internal pictures of an object by taking a large number of 2D images from different angles in a process known as X-ray microtomography. However, the new microscope is the first to combine this technique with time delay. It averages out imperfections in the image across all pixels enabling the microscope to produce clearer and bigger pictures than previously possible.

In X-ray microtomography, there are variations in the sensitivity of the pixels that make up the picture captured by the sensor. These feed into the final computer-generated 3D image, making it less clear. In the new microscope, a method called time delay integration is used, where the camera incorporating the sensor is moved through the X-ray shadow whilst collecting the X-ray image. At the same time, the image being created on the surface of the sensor is electronically shifted in the opposite direction. In this way, any imperfections are 'smoothed out' by averaging them over all pixels before the 3D image is generated. This makes the final image much higher quality. The use of time delay integration also allows larger objects to be examined without loss of image quality.

Among many potential applications, the microscope could be used to study how bone and tooth tissue behave in conditions such as osteoporosis, osteoarthritis and tooth decay. It could also be employed to investigate how crude oil is held in sandstone pores, to assist the development of more efficient ways of exploiting both offshore and onshore oil resources. Another potential application is investigating the mechanical behaviour of metals at a microscopic level for developing more reliable, more resilient and lighter materials. It could also be used in the detailed study of fossils embedded in rocks without having to remove and risk damaging them.

Professor Jim Elliott of Queen Mary, University of London, who led the project said, "As well as developing these microscopes to study subtle variations in internal structure, a main aim of ours is to work with the wider scientific community to identify problems where they could make a real contribution. There's no limit to what it would be useful or interesting to look at."

The team is currently planning to seek funding to support the development of a new design that they say could be even more effective.