Additions and corrections

Batch-mode mixing on centrifugal microfluidic platforms

M. Grumann, A. Geipel, L. Riegger, R. Zengerle and J. Ducrée

Lab Chip, 2005, 5, 560 (DOI: 10.1039/b418253g). Amendment published 4th August 2005

Eqns. (1), (3) and (5) should read:

On p. 563, Section entitled 'Mixing in alternate spinning mode', the second and third paragraphs should read:

To understand the origin of the mixing effect, we consider the change of the spinning frequency for a given fluid element spaced at a radial distance r from the center of rotation (Fig. 4). Inertia tends to stabilize its angular velocity ω = 2πν and thus the angular momentum. According to the given geometry, a difference in the angular momentum ΔΓω arises from the difference in radial position Δr.

This difference in the angular momentum translates into a shear force which drives an advective current within the fluid upon acceleration and deceleration. Mixing is promoted by a twisting pattern of the two fluids shown in Fig. 3B compared to mere deflection of the magnetic beads in constant spinning mode where the angular momentum Γω does not change in time to eliminate these inertially induced shear forces.

The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.