M. R. Pollard
S. W. Botchway
B. N. Chichkov
E. Freeman
R. N. J. Halsall
D. W. K. Jenkins
I. Loader
A. Ovsianikov
A. W. Parker
R. Stevens
R. Turchetta
A. D. Ward
M. Towrie

Optically trapped probes with nanometer-scale tips for femto-Newton force measurement

New Journal of Physics
11
12
113056
2010
Type: Zeitschriftenaufsatz (reviewed)
Abstract
We describe the development of a novel force probe, controlled by multiple optical traps, with a nanometer-scale tip that protrudes outside the direct laser radiation field. We have measured forces to an accuracy of 240 fN, which enables future experiments that probe photo-sensitive components (such as biological cells) and non-transparent objects. The probes were produced using two methods, electron beam lithography and two-photon polymerization, with the latter providing approximately twice as much trapping stiffness.