The NMR community has a long history of homebuilt instrumentation, particularly for applications in solid-state NMR and oriented liquids. The recent proliferation of applications involving biomolecular solids and complex materials have increased the stringency of specifications for NMR probe designs, making fabrication more difficult. In order to improve reproducibility and facilitate sharing successful designs among different laboratories, we have developed methodology for making precisely specified NMR transceiver coils using disposable 3D-printed templates.
This approach allows facile, reproducible production of coils of a particular geometry even in the hands of inexperienced researchers and makes it easier to share precisely specified coil designs with other labs. This has the potential to accelerate innovation in this area, in the same way that widespread sharing of pulse sequences has led to remixing of sequencing building blocks and the proliferation of specialized experiments based on a set of standard tools.
Here I will describe a strategy for producing optimized coils of a given geometry. First, the spatial characteristics of the coil are optimized based on simulation of the electric and magnetic fields in its vicinity. Then, the coil and its corresponding template are specified in a CAD program and the template is printed out, followed by fabrication of the coil. This approach can also be used to enable production of more complicated designs that are not easily wound by hand. Extensions of this methodology include making saddle coils that must be annealed, requiring heat-tolerant resin templates, 3D printing electrical-grade PTFE inserts suitable for use in the finished probe, and strategies for achieving and maintaining alignment of two coils in a crossed-coil design. Simulations and experimental (benchtop and NMR) measurements using different resonator designs will be discussed, along with new additive fabrication methods and future development of purpose-built NMR probes for specific applications.