Nanoscale resonators offer great potential as sensing devices due to their high sensitivity to added masses or external forces. The sensitivity of mechanical resonators scales favorably as their dimensions are reduced, offering a compelling path for the development of sensors with exceptional mass sensitivities. Nanomachining now allows the fabrication of mechanical objects with lateral dimensions of about 100 nm and resonant frequencies in the ultra-high frequency range. Given their small volumes and high surface-to-volume ratios, these nanoelectromechanical systems (NEMS) are of great interest for the detection of mass with high sensitivity.
The National Institute of Nanotechnology (NINT) is engaged in a series of state-of the art research programs related to the development and applications of nanomechanical resonators. Suspended resonators as narrow as 30 nm, the narrowest structures ever produced by any machining method, have been produced using a novel combination of surface nanomachining and bulk etching. Alternatively a partnership with Hewlett-Packard laboratories has recently enabled the production of clamped resonant nanowires with diameters as narrow as 20 nm. We will present an overview of those novel nanofabrication technologies, and discuss our efforts towards their applications for the analysis of molecular mixtures.