Abstract
Radiofrequency coil is one of the most important components for a nuclear magnetic resonance (NMR) instrument. In this article, some planar micro coils with an inner diameter of 2 mm and number of turns that varied from 1 to 11 were investigated based on the printed circuit board (PCB) technology. The electrical characterization of micro coils show that self-resonant frequencies are larger than 200 MHz. Then, an NMR measurement platform with a static magnetic field of 0.66 T was constructed and the signal to noise ratio (SNR) values of the NMR were analyzed. It was found that the SNR is optimal when the turn number of the micro coils is six and the excitation time of a 90° pulse is 0.8 ms. Finally, we used the micro coil with six turns to study the transverse relaxation rate of copper sulfate pentahydrate aqueous solution with different concentrations. It was found that the transverse relaxation rate is proportional to the solution concentration. Results from the micro coil were verified by measurements using a Bruker Minispec MQ60.
Similar content being viewed by others
References
Bajaj V S, Paulsen J, Harel E, et al. Zooming in on microscopic flow by remotely detected MRI. Science, 2010, 330: 1078–1081
Arai M, Ferreon J C, Wright P E. Quantitative analysis of multisite protein-ligand interactions by NMR: Binding of intrinsically disordered p53 transactivation subdomains with the TAZ2 domain of CBP. J Am Chem Soc, 2012, 134: 3792–3803
Kitevski-LeBlanc J L, Prosser R S. Current applications of 19F NMR to studies of protein structure and dynamics. Prog Nucl Magn Reson Spectrosc, 2012, 62: 1–33
Hoult D I, Richards R E. The signal-to-noise ratio of the nuclear magnetic resonance experiment. J Magn Reson, 1976, 24: 71–85
Magin R L, Webb A G, Peck T L. Miniature magnetic resonance machines. IEEE Spectrum, 1997, 34: 51–61
Wright A C, Neideen T A, Magin R L, et al. Evaluation of radio frequency microcoils as nuclear magnetic resonance detectors in low-homogeneity high-field superconducting magnets. Rev Sci Instrum, 1998, 69: 3938–3941
Moresi G, Magin R. Miniature permanent magnet for table-top NMR. Concepts Magn Reson Part B, 2003, 19B: 35–43
Peck T L, Magin R L, Lauterbur P C. Design and analysis of microcoils for NMR microscopy. J Magn Reson Ser B, 1995, 108: 114–124
Massin C, Boero C, Vincent F, et al. High-Q factor RF planar microcoils for micro-scale NMR spectroscopy. Sens Actuator A Phys, 2002, 97–98: 280–288
Massin C, Vincent F, Homsy A, et al. Planar microcoil-based microfluidic NMR probes. J Magn Reson, 2003, 164: 242–255
Hsieh C, Yeh Y, Fan L. Multilayer high-aspect-ratio RF coil for NMR applications. Microsyst Technol, 2011, 17: 1311–1317
Lam M H C, Homenuke M A, Michal C A, et al. Sub-nanoliter nuclear magnetic resonance coils fabricated with multilayer soft lithography. J Micromech Microeng, 2009, 19: 095001
Nguyen N T, Huang X Y. Miniature valveless pumps based on printed circuit board technique. Sens Actuator A-Phys, 2001, 88: 104–111
Gassmann S, Ibendorf I, Pagel L. Realization of a flow injection analysis in PCB technology. Sens Actuator A-Phys, 2007, 133: 231–235
Kong T F, Peng W K, Luong T D, et al. Adhesive-based liquid metal radio-frequency microcoil for magnetic resonance relaxometry measurement. Lab Chip, 2012, 12: 287–294
Wensink H, Hermes D C, van den Berg A. High signal to noise ratio in low field NMR on chip, simulations and experimental results. In: 17th IEEE International Conference on Micro Electro Mechanical Systems, Maastricht, the Netherlands, 2004
Wensink H, Benito-Lopez F, Hermes D C, et al. Measuring reaction kinetics in a lab-on-a-chip by microcoil NMR. Lab Chip, 2005, 5: 280–284
Fratila R M, Velders A H. Small-volume nuclear magnetic resonance spectroscopy. Ann Rev Anal Chem, 2011, 4: 227–249
Kratt K, Badilita V, Burger T, et al. A fully MEMS-compatible process for 3D high aspect ratio micro coils obtained with an automatic wire bonder. J Micromech Microeng, 2010, 20: 015021
Spengler N, Moazenzadeh A, Meier R C, et al. Micro-fabricated Helmholtz coil featuring disposable microfluidic sample inserts for applications in nuclear magnetic resonance. J Micromech Microeng, 2014, 24: 034004
Sillerud L O, McDowell A F, Adolphi N L, et al. H-1 NMR Detection of superparamagnetic nanoparticles at 1 T using a microcoil and novel tuning circuit. J Magn Reson, 2006, 181: 181–190
Seeber D A, Cooper R L, Ciobanu L, et al. Design and testing of high sensitivity microreceiver coil apparatus for nuclear magnetic resonance and imaging. Rev Sci Instrum, 2001, 72: 2171–2179
Manz B, Benecke M, Volke F. A simple, small and low cost permanent magnet design to produce homogeneous magnetic fields. J Magn Reson, 2008, 192: 131–138
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wu, W., Lu, R., Zhou, X. et al. Low-field NMR micro coils based on printed circuit board technology. Sci. China Technol. Sci. 57, 2082–2088 (2014). https://doi.org/10.1007/s11431-014-5609-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11431-014-5609-y