Skip to main content
SpringerLink
Log in

Development of a miniature permanent magnetic circuit for nuclear magnetic resonance chip

  • Published:
Chinese Journal of Mechanical Engineering Submit manuscript

Abstract

The existing researches of miniature magnetic circuits focus on the single-sided permanent magnetic circuits and the Halbach permanent magnetic circuits. In the single-sided permanent magnetic circuits, the magnetic flux density is always very low in the work region. In the Halbach permanent magnetic circuits, there are always great difficulties in the manufacturing and assembly process. The static magnetic flux density required for nuclear magnetic resonance(NMR) chip is analyzed based on the signal noise ratio(SNR) calculation model, and then a miniature C-shaped permanent magnetic circuit is designed as the required magnetic flux density. Based on Kirchhoff’s law and magnetic flux refraction principle, the concept of a single shimming ring is proposed to improve the performance of the designed magnetic circuit. Using the finite element method, a comparative calculation is conducted. The calculation results demonstrate that the magnetic circuit improved with a single shimming has higher magnetic flux density and better magnetic field homogeneity than the one improved with no shimming ring or double shimming rings. The proposed magnetic circuit is manufactured and its experimental test platform is also built. The magnetic flux density measured in the work region is 0.7 T, which is well coincided with the theoretical design. The spatial variation of the magnetic field is within the range of the instrument error. At last, the temperature dependence of the magnetic flux density produced by the proposed magnetic circuit is investigated through both theoretical analysis and experimental study, and a linear functional model is obtained. The proposed research is crucial for solving the problem in the application of NMR-chip under different environmental temperatures.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. MOGENSEN K B, KLANK H, KUTTER J P. Recent developments in detection for microfluidic systems[J]. Electrophoresis, 2004, 25(21–22): 3 498–3 512.

    Google Scholar 

  2. VANDAVEER W R, PASS-FARMER S A, FISCHER D J, et al. Recent developments in electrochemical detection for microchip capillary electrophoresis[J]. Electrophoresis, 2004, 25(21–22):3 528–3 549.

    Google Scholar 

  3. WHITESIDES G M. The origins and the future of microfluidics[J]. Nature, 2006, 442(7101): 368–373.

    Article  Google Scholar 

  4. HAREL E. Magnetic resonance detection: spectroscopy and imaging of lab-on-a-chip[J]. Lab on a Chip, 2009, 9(3): 17–23.

    Article  Google Scholar 

  5. LEE H, SUN E, HAM D, et al. Chip-NMR biosensor for detection and molecular analysis of cells[J]. Nature Medicine, 2008, 14(8): 869–874.

    Article  Google Scholar 

  6. HAUN J B, CASTRO C M, WANG R, et al. Micro-NMR for rapid molecular analysis of human tumor samples[J]. Science Transl. Med., 2011, 3(71): 71ra16.

    Article  Google Scholar 

  7. EIDMANN G, SAVELSBERG R, BLÜMLER P, et al. The NMR MOUSE, a mobile universal surface explorer[J]. Journal of Magnetic Resonance, 1996, 122(1): 104–109.

    Article  Google Scholar 

  8. PERLO J, DEMAS V, CASANOVA F, et al. High-resolution NMR spectroscopy with a portable single-sided sensor[J]. Science, 2005, 308(5726): 1 279–1 279.

    Article  Google Scholar 

  9. PERLO J, CASANOVA F, BLUMICH B. Ex situ NMR in highly homogeneous fields: H-1 spectroscopy[J]. Science, 2007, 315(5815):1 110–1 112.

    Article  Google Scholar 

  10. MARBLE A E, MASTIKHIN I V, COLPITTS B G, et al. A compact permanent magnet array with a remote homogeneous field[J]. Journal of Magnetic Resonance, 2007, 186(1): 100–104.

    Article  Google Scholar 

  11. DANIELI E, PERLO J, BLUMICH B, et al. Small magnets for portable NMR spectrometers[J]. Angew. Chem. Int. Ed., 2010, 49(24): 4 133–4 135.

    Article  Google Scholar 

  12. MORESI G, MAGIN R. Miniature permanent magnet for Table-top NMR[J]. Concepts in Magnetic Resonance Part B: Magnetic Resonance Engineering, 2003, 19B(1): 35–43.

    Article  Google Scholar 

  13. DEMAS V, HERBERG J L, MALBA V, et al. Portable, low-cost NMR with laser-lathe lithography produced microcoils[J]. Journal of Magnetic Resonance, 2007, 189(1): 121–129.

    Article  Google Scholar 

  14. VISKARI P J, LANDERS J P. Unconventional detection methods for microfluidic devices[J]. Electrophoresis, 2006, 27(9): 1 797–1 810.

    Article  Google Scholar 

  15. HOULT D I, RICHARDS R E. The signal-to-noise ratio of the nuclear magnetic resonance experiment[J]. Journal of Magnetic Resonance, 1976, 24(1): 71–85.

    Google Scholar 

  16. DEAN L O, TIMOTHY L P, ANDREW G W, et al. Highresolution microcoil 1H-NMR for mass-limited, nanoliter-volume samples[J]. Science, 1995, 270(5 244): 1 967–1 970.

    Google Scholar 

  17. WENSINK H, HERMES D C, VAN DEN BERG A. High signal to noise ratio in low field NMR on chip, simulations and experimental results[C]//IEEE International Conference on Micro Electro Mechanical Systems, Maastricht, Netherlands, January 25–29, 2004: 407–410.

  18. LU Rongsheng, WU Weiping, NI Zhonghua. Development of micro-permanent magnet magnetic circuit for nuclear magnetic resonance microscopy chip[J]. Journal of Southeast University (Natural Science Edition), 2011, 41(3): 533–537. (in Chinese)

    Google Scholar 

  19. WU Haicheng. Research on MRI magnet-system with CAD method[D]. Hefei: University of Science and Technology of China, 2007. (in Chinese)

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing, 211189, China

    Rongsheng Lu, Hong Yi, Weiping Wu & Zhonghua Ni

Authors
  1. Rongsheng Lu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Hong Yi
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Weiping Wu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Zhonghua Ni
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Zhonghua Ni.

Additional information

This project is supported by National Natural Science Foundation of China (Grant No. 51175083), Jiangsu Provincial University Industry Cooperation Innovation Foundation-Prospective Study of China (Grant No. BY2011135), Scientific Research Foundation of Graduate School of Southeast University, China (Grant No. YBJJ1134), and Important Scientific Research Guide Foundation of Southeast University, China

LU Rongsheng, born in 1985, is currently a PhD candidate at School of Mechanical Engineering, Southeast University, China. He received his bachelor degree on mechanical manufacture and automation from Chongqing University, China, in 2007. His research interests include miniature magnetic resonance instruments and biomedical instruments.

YI Hong, born in 1963, is currently director of Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, president of Southeast University, China, a professor and a PhD candidate supervisor at School of Mechanical Engineering, Southeast University, China. He received his PhD degree from Tsinghua University, China, in 1990. His main research interests include advanced manufacturing technology, theory, design and manufacture of micro-nanoelectronic mechanical systems.

WU Weiping, born in 1985, is currently a PhD candidate at School of Mechanical Engineering, Southeast University, China. He received his bachelor degree in mechanical engineering from Anhui University of Science and Technology, China, in 2006 and master degree in mechatronic engineering from Hefei University of Technology, China, in 2009. His research interests include miniature magnetic resonance instruments and biomedical instruments.

NI Zhonghua, born in 1967, is currently deputy director of Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, a professor and a PhD candidate supervisor at School of Mechanical Engineering, Southeast University, China. He received his PhD degree from Southeast University, China, in 2001. His main research interests include mechanical engineering, MEMS, biomedical instruments and microfluid chip.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lu, R., Yi, H., Wu, W. et al. Development of a miniature permanent magnetic circuit for nuclear magnetic resonance chip. Chin. J. Mech. Eng. 26, 689–694 (2013). https://doi.org/10.3901/CJME.2013.04.689

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.3901/CJME.2013.04.689

Key words

Search

Navigation