Volume 99, Number 5, September 2012
|Number of page(s)||6|
|Section||Interdisciplinary Physics and Related Areas of Science and Technology|
|Published online||13 September 2012|
Force sensing with a shaped dielectric micro-tool
1 H. H. Wills Physics Laboratory, University of Bristol - Bristol, BS8 1TL, UK, EU
2 SUPA, School of Physics and Astronomy, University of Glasgow - Glasgow, G12 8QQ, UK, EU
3 Department of Electrical and Electronic Engineering, University of Bristol - Bristol, BS8 1UB, UK, EU
Received: 9 July 2012
Accepted: 9 August 2012
We analyse the thermal motion of a holographically trapped non-spherical force probe, capable of interrogating arbitrary samples with nanometer resolution. High speed video stereo-microscopy is used to track the translational and rotational coordinates of the micro-tool in three dimensions, and the complete 6 × 6 stiffness matrix for the system is determined using equipartition theorem. The Brownian motion of the extended structure is described in terms of a continuous distribution of thermal ellipsoids. A centre of optical stress, at which rotational and translational motion is uncoupled, is observed and controlled. Once calibrated, the micro-tool is deployed in two modes of operation: as a force sensor with <150 femto-Newton sensitivity, and in a novel form of photonic force microscopy.
PACS: 87.80.Cc – Optical trapping / 81.07.-b – Nanoscale materials and structures: fabrication and characterization / 45.40.-f – Dynamics and kinematics of rigid bodies
© EPLA, 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.