News

May 20, 2023

The Raspberry Pi

Researchers from Lund University, the Lund Institute of Advanced Neutron and X-ray Science (LINXS), Argonne National Laboratory, and Northwestern University have released an open source tomographic

Researchers from Lund University, the Lund Institute of Advanced Neutron and X-ray Science (LINXS), Argonne National Laboratory, and Northwestern University have released an open source tomographic scanner that uses visible light — allowing for advanced imaging right in your kitchen.

"We present a recipe for building a portable DIY toolkit, entitled Kitchen-Based Light Tomography (KBLT), for performing tomography using visible light with low-cost and easily accessible components," the research team explains of the project, brought to our attention by the Raspberry Pi blog. "All the software for motor controls, image acquisition, image reconstruction and analysis is open sourced and available online."

Tomography, also known as tomographic imaging, uses penetrating waves to take a "tomogram" of not only the surface of objects but inside them too — taking two-dimensional cross-sections of a three-dimensional object, hence "tomo" meaning "slice." Typically, tomographs are expensive pieces of equipment which rely on X-ray or neutron sources, but the KBLT is designed to be both affordable and safe for amateur or beginner experimentation — so uses a suitably strong LED flashlight instead.

The exact capabilities of a KBLT depend on how it's made. Its designers say that beginners can put together a simple version, dubbed KBLT v1, from LEGO bricks, a mobile phone, a flashlight, and a paper screen. KBLT v2, meanwhile, provides automation and an experience more like the professional-grade devices you'd find in a lab — and is built using a Raspberry Pi single-board computer, a flashlight, a webcam, and a motorized rotation stage controlled by the Raspberry Pi's general-purpose input/output (GPIO) header.

"Depending on the utilized hardware and design, a safe and cost efficient KBLT scanner for educational purposes can be constructed for as little as €150 to €1,000 [around $164-$1,100]," the researchers estimate, "which should be put in contrast to the cost of around €37k [around $40,420] for buying an X-ray-based scanner for educational purposes or [a] full lab-based X-ray scanner costing €100k to €1.5M [around $110,000 to $1.64 million]."

"KBLT has been [designed] as a practical educational tool, to train new and future users of LSRIs [Large-Scale Research Infrastructures] in tomography, as well as its potential usefulness for both beamline scientists and computational researchers in their normal workflow for testing and improving hardware and software solutions, including novel reconstruction algorithms," its creators claim.

"By using KBLT," the researchers continue, "it is possible to lower the threshold for the very first tomography experiment at an LSRI, using either X-rays or neutrons. Future endeavors could build on the KBLT concept to establish more training and development tools for other type of techniques, e.g., scattering, diffraction and spectroscopy, which will further increase the knowledge and know-how of the next generation of users, beamline scientists and computational researchers of LSRIs."

The paper detailing the project has been published under open-access terms in the journal Tomography of Materials and Structures, while the source code and assembly instructions — plus a link to gathered KBLT datasets, including a Python reconstruction script — are available on GitHub under the permissive BSD three-clause license.