TY - JOUR
T1 - Force sensing with a shaped dielectric micro-tool
AU - Phillips, D.B.
AU - Simpson, S.H.
AU - Grieve, J.A.
AU - Bowman, R.
AU - Gibson, G.M.
AU - Padgett, M.J.
AU - Rarity, J.G.
AU - Hanna, S.
AU - Miles, M.J.
AU - Carberry, D.M.
PY - 2012/9/12
Y1 - 2012/9/12
N2 - 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.
AB - 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.
UR - https://doi.org/10.1209/0295-5075/99/58004
U2 - 10.1209/0295-5075/99/58004
DO - 10.1209/0295-5075/99/58004
M3 - Article
SN - 0295-5075
VL - 99
JO - EPL (Europhysics Letters)
JF - EPL (Europhysics Letters)
IS - 5
M1 - 58004
ER -