Critical view on new results in micro-fluid mechanics: an example

Experiments in micro-flow devices almost always show deviations compared to the corresponding situations in macro-systems. Often special micro-effects are proposed to explain these unexpected results. However, based on a nondimensional form of the problem formulation these micro-effects can be identified as scaling effects referred to a standard analysis in macro-dimensions. Thus many unexpected results can be explained. This is demonstrated for a specific example recently published in this journal. (C) 2002 Elsevier Science Ltd. All rights reserved.