Metallized, 3D-printed radiofrequency coils.

Area of Science:

• Magnetic Resonance Spectroscopy
• Materials Science
• Engineering

Background:

• Radiofrequency (RF) coils are critical components in nuclear magnetic resonance (NMR) but are typically limited to conventional geometries due to fabrication constraints.
• Existing methods restrict RF coil design, hindering performance optimization for advanced NMR techniques.

Purpose of the Study:

• To present a practical method for fabricating complex, high-performance RF coils using stereolithographic (SLA) 3D printing and copper metallization.
• To develop a computational tool for optimizing RF coil performance based on 3D-printable designs.
• To demonstrate an improved RF coil design for magic-angle spinning (MAS) solid-state NMR.

Main Methods:

• Utilized stereolithographic (SLA) 3D printing for complex coil structures, followed by a two-stage copper plating process for robust metallization.
• Developed a quasi-static magnetic field modeling program for direct simulation and numerical optimization of 3D-printable coil geometries.
• Designed, simulated, and fabricated an optimized variable-pitch, tilted-helix solenoid for MAS solid-state NMR.

Main Results:

• Achieved mechanically robust, copper-coated RF coils suitable for high-power MAS solid-state NMR.
• The optimized solenoid design demonstrated a 24.3% increase in transverse RF field strength compared to conventional solenoids.
• Spatially resolved nutation imaging revealed an 11.5% extension in the region of uniform RF excitation.

Conclusions:

• Stereolithographic 3D printing followed by copper metallization offers a versatile approach for fabricating advanced RF coils.
• The developed modeling program facilitates the design of customized RF coils with enhanced performance.
• This fabrication and design methodology enables the creation of RF coils tailored for specific, demanding NMR applications, moving beyond traditional constraints.