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Heteronuclear micro-helmholtz coil facilitates μm-range spatial and sub-Hz spectral resolution NMR of nL-volume samples on customisable microfluidic chips

Spengler, N.; Höfflin, J.; Moazenzadeh, A.; Mager, D.; MacKinnon, N.; Badilita, V.; Wallrabe, U.; Korvink, J.G.

Abstract:
We present a completely revised generation of a modular micro-NMR detector, featuring an active sample volume of ∗ 100 nL, and an improvement of 87% in probe efficiency. The detector is capable of rapidly screening different samples using exchangeable, applicationspecific, MEMS-fabricated, microfluidic sample containers. In contrast to our previous design, the sample holder chips can be simply sealed with adhesive tape, with excellent adhesion due to the smooth surfaces surrounding the fluidic ports, and so withstand pressures of ∗2.5 bar, while simultaneously enabling high spectral resolution up to 0.62 Hz for H2 O, due to its optimised geometry. We have additionally reworked the coil design and fabrication processes, replacing liquid photoresists by dry film stock, whose final thickness does not depend on accurate volume dispensing or precise levelling during curing. We further introduced mechanical alignment structures to avoid time-intensive optical alignment of the chip stacks during assembly, while we exchanged the laser-cut, PMMA spacers by diced glass spacers, which are not susceptible to melting during cutting. Doing so led to an overall simplification of the entire fabrication chain, while simultaneously increasing the yield, due to an improved uniformity of thickness of the individual layers, and in addition, due to more accurate vertical positioning of the wirebonded coils, now delimited by a post base plateau. ... mehr

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Verlagsausgabe §
DOI: 10.5445/IR/1000052541
Veröffentlicht am 26.09.2018
Originalveröffentlichung
DOI: 10.1371/journal.pone.0146384
Scopus
Zitationen: 25
Web of Science
Zitationen: 24
Coverbild
Zugehörige Institution(en) am KIT Institut für Mikrostrukturtechnik (IMT)
Publikationstyp Zeitschriftenaufsatz
Jahr 2016
Sprache Englisch
Identifikator ISSN: 1932-6203
urn:nbn:de:swb:90-525418
KITopen-ID: 1000052541
HGF-Programm 47.02.07 (POF III, LK 01)
Erschienen in PLoS one
Band 11
Heft 1
Seiten e0146384
Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds
Nachgewiesen in Scopus
Web of Science
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