Abstract:

The detection of trace samples holds extensive application demands in fields such as environmental monitoring, biological sciences, and medicine. Conventional magnetic resonance probes suffer from low filling factors, which can reduce the signal-to-noise ratios (SNR) for microsamples. Microcoils matching sample sizes improve sensitivity and SNR. The need for efficient solutions is further highlighted by the demand for broadband detection, with a desire to reduce the number of experimental steps during sample analysis and shorten detection times, as commercial probes are very complex and need to be retooled. This study designed a multilayer solenoid microcoil with excellent field uniformity, low inductance, and resistance. The coil was fabricated using printed circuit board (PCB) technology and tested on a 1.5 T MRI system magnet equipped with a custom broadband RF front end, where multiple nuclei (¹H, ²H, ⁷Li, ¹⁹F) were detected in 250 nL samples, demonstrating broadband capability and high sensitivity. The results highlight its potential for efficient and versatile microsample analysis.

Key words: NMR, microcoil, broadband, PCB