Abstract: A method for fabricating MAS NMR rotors and drive caps made of diamond to increase the maximum achievable spinning frequency and enhance MAS NMR sensitivity and resolution. Diamond is an excellent choice for making MAS NMR rotors due to its high tensile and flexural strength, however, micromachining diamond is difficult due to its hardness. Although laser cutting is often employed to cut diamond sheets, this process cannot be used to create the high aspect ratio and small features required for MAS NMR rotors. In the present invention, a laser micromachining process is used to create the desired high aspect ratio while maintaining the small lateral features. In this process, the laser is used to first convert the diamond into graphite followed by a conversion to carbon dioxide in the presence of oxygen. To create a rotor, a rectangular log has a center hole drilled by the laser, and is then micromachined into a hollow cylinder.

Abstract: A method for fabricating MAS NMR rotors and drive caps made of diamond to increase the maximum achievable spinning frequency and enhance MAS NMR sensitivity and resolution. Diamond is an excellent choice for making MAS NMR rotors due to its high tensile and flexural strength, however, micromachining diamond is difficult due to its hardness. Although laser cutting is often employed to cut diamond sheets, this process cannot be used to create the high aspect ratio and small features required for MAS NMR rotors. In the present invention, a laser micromachining process is used to create the desired high aspect ratio while maintaining the small lateral features. In this process, the laser is used to first convert the diamond into graphite followed by a conversion to carbon dioxide in the presence of oxygen. To create a rotor, a rectangular log has a center hole drilled by the laser, and is then micromachined into a hollow cylinder.