Optical Sciences

Biomolecules and nanostructures

The Optical Sciences group studies the interaction of light and matter at the nanoscale. We do this by exploring ways to shape light and its environment. It's what we call active and passive control. Our current focus is on the interaction of light with biomolecules and nanostructures. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.
We participate in the EU-COST actions MP1102: Coherent Raman microscopy (MicroCor) and CM1202: Supramolecular photocatalytic water splitting (PERSPECT-H2O)

 

Height anomalies in tapping mode atomic force microscopy in air caused by adhesion

(full pdf)

VanNoort SJT, VanderWerf KO, DeGrooth BG, VanHulst NF, Greve J
ULTRAMICROSCOPY
vol 69 issue 2: p117-p127 SEP 1997

Height anomalies in tapping mode atomic force microscopy (AFM) in air are shown to be caused by adhesion. Depending o­n the damping of the oscillation the height of a sticking surface is reduced compared to less sticking surfaces. It is shown that the height artefacts result from a modulation of oscillatory movement of the cantilever. Damping and excitation of the cantilever by the driver continuously compete. As a consequence a severe modulation of the cantilever oscillation occurs, depending o­n the phase mismatch between the driver and the cantilever. Phase images of tapping a mode AFM show contrast which correlates with adhesion. Examples of a partially removed gold layer o­n mica, a Langmuir-Blodgett film and DNA show height artefacts ranging up to 10 nm.
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