Twin cantilevers with a nanogap for single molecule experimentation

Single molecule experiments aimed both at fundamental investigation and applications, have been, recently, attracting a lot of attention. Most of the devices used for the detection and the manipulation of single molecules are based on very expensive lithographic tools, need a specific molecule labelling or functionalization and still show many limitations. We propose here an alternative approach based on the fabrication of pair of identical silicon cantilevers (the twin cantilevers), separated by a gap that is tuneable on the nanometric scale. The fabrication and operation of our twin cantilever device involves only the use of standard optical lithography and micrometric manipulation. We have investigated the frequency response of the twin cantilever device around its fundamental resonance, and, by modelling its behaviour, we show that a single molecule, spanning the cantilever gap, can, on paper, be detected. (c) 2006 Elsevier B.V. All rights reserved.