Design of the Broadband Magnetic Resonance Microcoil

doi:10.11938/cjmr20253148

Abstract

Abstract:

The detection of microsamples holds extensive application demands in fields such as environmental monitoring, biological sciences, and medicine. When conventional magnetic resonance probes are used to detect microsamples, the smaller filling factors lead to reduced signal-to-noise ratios (SNR) in magnetic resonance detection. Using microcoils comparable in size to the microsamples can significantly improve detection sensitivity and enhance SNR. Furthermore, due to the growing demand for broadband detection, there is a desire to reduce experimental steps during sample analysis and shorten detection times. However, currently available commercial probes are not designed for microsample detection and are relatively too complex to meet the requirements for efficient and convenient applications. To address these issues, 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 self-developed spectrometer and 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: nclear magnetic resonance (NMR), microcoil, broadband, printed circuit board (PCB)

CLC Number:

O482.53

JIANG Chaochao, YAO Shouquan, XU Juncheng, JIANG Yu. Design of the Broadband Magnetic Resonance Microcoil[J]. Chinese Journal of Magnetic Resonance, 2025, 42(3): 299-307.

Figures/Tables 8

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Table 1

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参数名称	参数设置
原子核	²H	⁷Li	¹⁹F	¹H
样品	99%重水	11.5%六氟磷酸锂溶液	99. 04%六氟苯溶液	4%硫酸铜溶液
中心频率	9.80 MHz	24.52 MHz	60.10 MHz	63.88 MHz
接收带宽	100 kHz	100 kHz	50 kHz	250 kHz
射频脉宽	45 μs	28 μs	15 μs	15 μs
发射功率	30%	20%	16%	14.5%
累加次数	100	500	50	50