AFM topography (top) and adhesion (bottom) images of bacteria, Deinococcus radiodurans, acquired in a dry box with a clean SiO2 AFM probe. There are two full cells in the image, note the enhanced contrast in the finer scale structure displayed in the adhesion image.
INL is advancing the science of molecular surface analysis (nanotribology) by enhancing the performance of atomic force microscopy.
Simply defined, nanotribology is the molecular (and finer) scale study of interacting surfaces in relative motion. It has naturally evolved from the macroscopic tribology and concerns quantifying properties such as friction, adhesion, lubrication, and wear. Due to the scale and infinitesimal quantities inherent with molecules, nanotribology requires very sensitive instrumentation. Atomic force microscopy (AFM) is invaluable tool for measuring and assessing most of these properties.
Our goals in this area are two-fold: first, using our expertise in synthetic chemistry and surface science we want to tailor the AFM probe in a manner that provides us with the highest quality information pertaining to nanotribological interactions between surfaces. Second, we wish to increase the chemical sensitivity of AFM as single molecule analytical probe. With respect to both of these goals, the AFM-generated force curves may hold a plethora of information. With proper calibration, these force curves contain information about the attractive (sticky) forces in both the plane normal to the surface, the adhesion plane, and the plane parallel to the surface, the friction plane. The interaction between the two surfaces during AFM probe retraction (in either plane) can be exploited, as the chemical makeup (functional termini) of the two determines the force of interaction (see Figure 1). By ‘chemically tuning’ AFM probe composition, we hope to provide increased chemical sensitivity. Using special electronics, mapping of the chemistry can be performed.
Apparati: For more information about these instruments, see the capabilities page.
- Molecular Imaging PicoSPM
- Witek Pulsed Force Modulation Unit
- FEI Environmental Scanning Electron Microscope (ESEM)
- Perkin-Elmer Phi 4300 Scanning Auger Microprobe (SAM)
- Perkin-Elmer Phi 5300 X-ray Photoelectron Spectrometer (XPS)
- First Ten Angstroms FTA-200 Contact Angle Instrument
Peer-Reviewed Publications:
wo Invention Disclosure Records (IDR) have been filed for patent protection of two separate technologies developed from research in this project
- Contact:
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Patrick Pinhero, (208) 526-2285, Send E-mail
Tedd Lister, (208) 526-4320, Send E-mail