5988.1:
Scanning Force Microscopy with Ultrasmall Cantilevers (Project of the TOP NANO 21 Innovation Committee)
Abstract
The atomic force microscope (AFM) offers the observation of single biomolecules in their native environments with unprecedented resolution and signal-to-noise ratio. AFM at low temperatures and in UHV allows the atomic resolution imaging and measurement of conservative and dissipative forces acting between single atoms. Another important application of AFM in vacuum is the measurement of magnetic forces, i.e. the imaging of small magnetic structures with high spatial resolution.
Biomolecules move in the ms-regime. To observe them at work in real time, cantilevers with resonance frequencies in the MHz range but low force constants are required. This is achieved by reducing the dimensions of current cantilevers by at least an order of magnitude. Such small cantilevers also provide a higher force sensitivity that will enhance the distinction of the various physical and chemical mechanisms contributing to the interaction of single atoms and to analyze atomic scale energy loss processes. All these projects have in common that new types of ultrasmall cantilevers and new deflection sensors need to be developed. The fabrication of ultrasmall cantilevers will be based on IBM technology that has recently been developed for the manufacturing of millipede cantilever arrays. The deflection sensor is a completely new development of the Basel University (patent application running).