Multi-purpose 3-axis robot with submillimeter resolution. Possible applications: static/dynamic field mapping, CNC machinery, 3D printing etc.


Haopeng Han1, Raphael Moritz 1, Eva Oberacker 1, Helmar Waiczies 3, Thoralf Niendorf1,2,3, Lukas Winter4


Estimated cost

€ 2.000


v1.0 (CERN OHL v1.2)



Discussions: Channel #cosi_measure in our Slack Team

Cost effective open source imaging (COSI) is a collaborative initiative currently building an affordable low field open source MR scanner. COSI Measure is an open source multipurpose 3-axis robot, that can be equipped with field mapping probes for static or dynamic field measurements (electromagnetic, temperature etc.). Submillimeter fidelity and reproducibility/backlash performance were evaluated experimentally. It can be potentially upgraded to be used as a CNC, for 3D printing or other applications, that require reproducible submillimeter movements. The system can be easily scaled to smaller volumes and lighter/cheaper materials (CAD files available).

System specifications:

Dimension: (80x90x105)cm³
Working volume: (53x53x64)cm³
Precision: positioning error <1mm
Speed: 37mm/s
Max load: 21kg
Applied force: 896N (91kg)
Standalone system: Beagle Bone Black, ARM Contex-A8 1GHz, 512MB DDR3, Programmable real-time unit subsystem
Inductive limit switches
Emergency stop button
Software: GUI (python)

Mapping the magnetic field of a Halbach magnet:

Mapping the stray magnetic field of a 3T MRI:

More videos can be found here (in the Electronic supplementary material).



1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine, Berlin, Germany
2Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine, Berlin, Germany
3MRI.TOOLS GmbH, Berlin, Germany
4Physikalisch Technische Bundesanstalt (PTB), Berlin, Germany


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