When you hear Superman, you might think of flight, strength, or even heat vision, but a material scientist would be far more impressed with the superhero’s ability to see through objects, clearly observing what is hidden within. While humans are unlikely to develop this ability any time soon, a powerful, non-destructive tomography technique called micro-computed tomography (microCT) may bring us one step closer.
How does microCT work?
When you expose a sample to an X-ray beam, some of the X-rays are absorbed by the sample; the rest of the X-rays travel through the sample and are collected by a detector, resulting in a 2D projection image. Then you rotate the sample slightly and take another 2D projection image. You perform this step multiple times. The now-collected 2D images are reconstructed to a virtual 3D volume giving structural information of your sample without destroying it. Taller samples need several of these 2D acquisitions with the conventional circular microCT; however, more advanced techniques, such as those implemented in the Thermo Scientific HeliScan by Thermo Fisher Scientific, can collect this data in one long, helical sweep.
The beauty of microCT is that it can be applied to almost any sample: from batteries to composite metals to an entire hornet, as imaged by Ohio State University’s Center for Electron Microscopy and Analysis (CEMAS) using our HeliScan:
Why does it matter?
While you may be familiar with X-ray tomography on the macroscale, especially if you’ve received a medical x-ray at some point in your life, microCT allows you to obtain unparalleled information below 0.4 micrometer in resolution, as seen in the AlSi-sample below:
How can I learn more?
Dirk Laeveren is Product Marketing Manager, Electron Microscopy at Thermo Fisher Scientific.