Now, a novel technique to separate molecules and nanoparticles by their polarizability to mass ratio in the gas phase has been reported by Hendrik Ulbricht and co-workers from the University of Vienna, Austria. Based on Talbot-Lau matter wave deflectometry the group has previously showed that molecule properties like polarizabilities can be measured in free flight with high precision (Phys. Rev. A 76 013607, 2007).
The first demonstrations of the ability to sort molecules were done by separating fullerenes out of a mixture by masking out molecules at different deflection angels. Theoretical estimates show the high potential of this technique for the sorting of biomolecules, such as polypeptides, and metallic and semiconducting SWNTs (Nanotechnology 19 045502, 2008).
Individual flying SWNTs of a defined metallic gender would open the door to applications of nanotube thin-films and single nanotube devices. Most challenging from an experimental point of view is the generation of beams of individual nanoparticles. The group is currently working towards this.