Optical Sciences

Biomolecules and nanostructures

The Optical Sciences group studies the interaction of light and matter. Our current focus is on detection and sensing/imaging with an emphasis on the development of integrated photonics. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.


Shear force imaging of soft samples in liquid using a diving bell concept

(full pdf)

M. Koopman, B. I. de Bakker, M. F. Garcia-Parajo, and N. F. van Hulst
Applied Physics Letters
Vol 83, Issue 24, pp. 5083-5085, Dec 15, 2003

We present a reliable and easy-to-use system, with a perfect analogy to a diving bell, to perform tuning fork based shear force microscopy o­n soft cells in liquid. Using the diving bell concept the tuning fork vibrates in air, while the tip is immersed in solution. In this way Q factors of 200 and higher in liquid are routinely obtained. The force feedback is reliable and stable over hours requiring a minimum adjustment of the set-point during imaging. With this system, tip-sample interaction forces are kept below 350 pN, enabling us to image soft dendritic cells in a buffer solution. ©2003 American Institute of Physics.
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