Arrays of IC-assisted 3D-microcoils for wideband NMR spectroscopy

J. Anders1, J. Handwerker1, M. Ortmanns1, R. Kamberger2, J.G. Korvink3 and O.G. Gruschke3

1Institute of Microelectronics, University of Ulm, D-89081 Ulm, Germany, 2BrainLinks-BrainTools Cluster of

Excellence, University of Freiburg, Germany, 3Institute of Microstructure Technology (IMT), Karlsruhe Institute of

Technology, Germany

Wideband NMR detectors have recently gained increasing attention in the NMR community as atool to perform multinuclei NMR experiments on a larger variety of nuclei compared to multi-tunedcoils. It has been shown in [1] that by using dedicated, miniaturized detection coils, the sensitivitywhich is achievable in such broadband NMR experiments is comparable to or even higher than withtuned detection coils. Additionally, the broadband NMR setup allows to straightforward conduct het-eronuclear NMR experiments both in coupled and decoupled mode with virtually any combination ofnuclei inside the bandwidth of the broadband detector [1]. In our proposed talk we will present mea-sured data from a prototype NMR detector array for high-throughput wideband NMR spectroscopyaccording to Fig. 1a. The system consists of two linear four-coil arrays and two dedicated CMOSASICs each containing four broadband low-noise receivers. Compared to our previously presentedsystem [2], the prototype displays two important improvements: Due to an improved manufacturingprocess the 3D-microcoils provide a filling factor of 100% and the improved noise performance ofthe receiver electronics removes the need for a tuning capacitor thereby enabling a true widebandoperation from approximately 1MHz to 1GHz, cf. Fig. 1b.

500 µm

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µcoil 4CMOS chip

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Figure 1: (a) Center: Rendering of the presented IC-assisted array of µNMR coils. Left zoom-in: Micrograph of theCMOS ASIC containing for low noise broadband NMR frontends. Right zoom-in: Micrographs of the 3D-microcoils usedas NMR detectors. (b) Simulated (parasitics extracted) gain and noise performance of the receivers.

References

[1] Fratila, R.M., Gomez, M.V., Sykora, S., Velders, A.H. (2014) Multinuclear nanoliter one-dimensional and two-dimensional nmr spectroscopy with a single non-resonant microcoil.Nature Communications, 5, 2014.

[2] Badilita, V., Kratt, K., Baxan, N., Anders, J., Elverfeldt, D., Boero, G., Hennig, J., Ko-rvink, J.G., Wallrabe, U. (2011) 3d solenoidal microcoil arrays with cmos integrated ampli-fiers for parallel mr imaging and spectroscopy, Micro Electro Mechanical Systems (MEMS),2011 IEEE 24th International Conference on, 809–812.