Microfabrication of Helmholtz Coils with Integrated Channels for NMR Spectroscopy

Abstract

A new technology for the microfabrication of Helmholtz microcoils with integrated SU-8 channels for NMR spectroscopy is presented.These Helmholtz microcoils demonstrate superior NMR performance regarding spin excitation uniformity compared to planar microcoils.The improved spin excitation uniformity opens the way to advanced chemical analysis using complex RF-pulse sequences.The fabricated Helmholtz coils have Q-factor greater than 20 due to electroplated coil turns and vias, which connect the upper and lower turns. The laminated SU-8 microchannel technology allows the implementation of further fluidic functions. Analyzing living cells, mechanical filters can be integrated for sample concentration and enhanced detection.

A Stripline-Type Inductor Used for NMR Detection

“…And the SNR will reduce if homogeneity is not good. The Spin Excitation Uniform (SEU) can represent the homogeneity [5]. It is defined as the ratio of the signal amplitudes produced by 810°pulse and that of 90° (Eq.6).…”

Microfluidic Overhauser DNP chip for signal-enhanced compact NMR

“…Micro NMR systems based on CMOS integrated circuits [3][4][5][6] as well as advances in micro-fabrication and lab-on-a-chip technologies 7,8 are further advancing miniaturisation, ultimately evolving towards handheld systems suitable for point-of-care and personalised diagnosis. Particularly, microfabricated NMR probes [9][10][11][12][13][14][15][16][17] can provide the efficient analysis of volume limited samples and even co-integrate new functionalities to enable novel analytic approaches, such as NMR in situ electrochemistry.…”