This is quite impressive, given the tight tolerances typically required for NMR instrumentation for Magic-Angle-Spinning (MAS) NMR experiments.
Xu, Ke, Oliver Pecher, Marco Braun, and Jörn Schmedt auf der Günne. “Stable Magic Angle Spinning with Low-Cost 3D-Printed Parts.” Journal of Magnetic Resonance 333 (December 1, 2021): 107096. https://doi.org/10.1016/j.jmr.2021.107096.
A 3D-printed double-bearing magic angle spinning (MAS) system was developed with a home-built 4.0 mm MAS nuclear magnetic resonance (NMR) probe at 7 T. Various fused deposition modelling 3D printers were used to produce spinning modules of ignorable materials costs for rotors with a diameter of 7.0, 4.0, and 3.5 mm. High-performance MAS experiments on the 4.0 mm-diameter model using a pencil-type ceramic rotor and 3D-printed drive cap resulted in a high-resolution 1H NMR signal of silicone grease. The 3.5 mm-diameter MAS system reached a spinning frequency of 23 kHz. Furthermore, 3D-printed inserts were designed for various rotor sizes which can isolate the sample from humidity for a duration of more than a week. Single crystal inserts for MAS rotors of commercial probes can readily be printed using two-color printers. Those developments enable customized low-cost MAS NMR for both adapting existing and manufacturing new probes, respectively.