Design Engineering

New nano-CT device creates high-resolution 3D x-rays of tiny objects


Quality Medical 3D imaging NDT

A team from the Technical University of Munich (TUM) developed a Nano-CT device that creates 3D x-ray images at resolutions up to 100 nanometers.

Although Computer Tomography (CT) has come a long way in recent times and is quickly becoming a go-to imaging technique. However, when it comes to imaging extremely small objects, the technology falls short.

A team from the Technical University of Munich (TUM) have found a solution for this problem — a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers.

Nano-CT imaging

Left: Surface of the leg. Right: A view inside the tissue with muscle fibers highlighted. Photo credit: Müller, Pfeiffer / TUM / reproduced with permission from PNAS.

For a first test application, the team, along with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht analyzed the locomotory system of a velvet worm.

The internal system of the velvet worm was x-rayed and a detector measures the respective amount of radiation absorbed from various angles. 3D images of the inside can be constructed based on several such measurements. For now, the new method is limited to scanning the tiny, 0.4 millimeter long legs of the velvet worm (Onychophora).


The TUM Nano-CT system is based on a newly developed x-ray source. The source generates a focused beam, without relying on x-ray optics. In combination with an extremely low-noise detector, the device produces images that approach the resolution possible with a scanning electron microscope, while also capturing structures under the surface of the object under investigation.

“We can make tomographies of significantly larger samples and we are more flexible in terms of the materials that can be investigated,” says TUM scientist Mark Müller, lead author of the PNAS article.

This new method was ideal for research led by Prof. Georg Mayer, head of the Department of Zoology at the University of Kassel.

The scientists investigate the evolutionary origin of arthropods with their current research focuses on velvet worms (onychophorans). The exact zoological classification of these ancient animals is still a matter of controversy; presumably, they share a common ancestor with arthropods and tardigrades (water bears).

The Nano-CT images make it possible to investigate the individual muscle strands of the velvet worm leg.

The new device was developed and installed at the Munich School of BioEngineering (MSB) and the team’s goal is to expand beyond testing biological samples, such as the velvet worm leg.

“In the future, this technology will also make biomedical investigations possible,” explains Franz Pfeiffer, TUM Professor for Biomedical Physics, Director of the MSB, and a Fellow at the TUM Institute for Advanced Study (TUM-IAS).

The team hopes to use the method to examine tissue samples to clarify whether or not a tumor is malignant. 3D non-destructive testing of tissue with a resolution like that of the Nano-CT can provide insights into the microscopic development of widespread illnesses such as cancer.



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