High- Q factor RF planar microcoils for micro-scale NMR spectroscopy

• Published in: Sensors and actuators. A, Physical Physical, 2002-04, Vol.97, p.280-288
• Main Authors: Massin, C., Boero, G., Vincent, F., Abenhaim, J., Besse, P.-A., Popovic, R.S.
• Format: Article
• Language: English
• Subjects: Applied sciences; Detection methods; Electronics; Exact sciences and technology; High quality factor; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical instruments, equipment and techniques; Micro- and nanoelectromechanical devices (mems/nems); Micromechanical devices and systems; Nuclear magnetic resonance; Physics; RF microcoil; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/S0924-4247(01)00847-0

We present the design, fabrication and test of high- Q factor radiofrequency planar microcoils for nuclear magnetic resonance (NMR) spectroscopy in small volume samples. The coils are fabricated on glass wafers using high-aspect ratio SU-8 photoepoxy and copper electroplating. On-wafer electrical characterization shows quality factors up to 40 at 800 MHz. A 500 μm diameter microcoil with a measured quality factor of 24 at 300 MHz is mounted on a printed circuit board and electrically contacted using aluminum wire bonding. This probe is inserted in a 7 T-superconducting magnet, and a 1 H -NMR spectrum of 160 nl ethylbenzene contained in a capillary placed over the microcoil is acquired in a single scan. This work is an important step towards the integration of NMR detection into micro-total analysis systems (μTAS).