TY - JOUR
T1 - Characterizing Concentrated, Multiply Scattering, and Actively Driven Fluorescent Systems with Confocal Differential Dynamic Microscopy
AU - Lu, Peter J.
AU - Giavazzi, Fabio
AU - Angelini, Thomas
AU - Zaccarelli, Emanuela
AU - Jargstorff, Frank
AU - Schofield, Andrew B
AU - Wilking, James
AU - Romanowsky, Mark
AU - Weitz, David
AU - Cerbino, Roberto
PY - 2012/5/22
Y1 - 2012/5/22
N2 - We introduce confocal differential dynamic microscopy (ConDDM), a new technique yielding information comparable to that given by light scattering but in dense, opaque, fluorescent samples of micron-sized objects that cannot be probed easily with other existing techniques. We measure the correct wave vector q-dependent structure and hydrodynamic factors of concentrated hard-sphere-like colloids. We characterize concentrated swimming bacteria, observing ballistic motion in the bulk and a new compressed-exponential scaling of dynamics, and determine the velocity distribution; by contrast, near the coverslip, dynamics scale differently, suggesting that bacterial motion near surfaces fundamentally differs from that of freely swimming organisms.
AB - We introduce confocal differential dynamic microscopy (ConDDM), a new technique yielding information comparable to that given by light scattering but in dense, opaque, fluorescent samples of micron-sized objects that cannot be probed easily with other existing techniques. We measure the correct wave vector q-dependent structure and hydrodynamic factors of concentrated hard-sphere-like colloids. We characterize concentrated swimming bacteria, observing ballistic motion in the bulk and a new compressed-exponential scaling of dynamics, and determine the velocity distribution; by contrast, near the coverslip, dynamics scale differently, suggesting that bacterial motion near surfaces fundamentally differs from that of freely swimming organisms.
U2 - 10.1103/PhysRevLett.108.218103
DO - 10.1103/PhysRevLett.108.218103
M3 - Article
VL - 108
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
M1 - 218103
ER -