Fabrication of NMR - microsensors for nanoliter sample volumes

The fabrication of micro-sensors for NMR-spectroscopy on both glass and GaAs is presented. Planar coils with inner diameter from 50 mu m to 400 mu m including a coplanar wave-guide leading to the bonding pads were combined with a chamber for liquid samples of 200-500 mu m diameter on the backside of the substrate. The microcoil served as a receiver in a H-1-NMR experiment at 11T(500 MHz). In initial experiments, the spectrum of 60 nl-volumes of pure silicone-oil were detected by the microcoil.