Preface to special topic: papers from the 2009 conference on advances in microfluidics and nanofluidics, the Hong Kong university of science & technology, Hong Kong, 2009.

The inaugural conference on Advances in Microfluidics and Nanofluidics was held at the Hong Kong University of Science and Technology on 5-7 January 2009 and brought together leading researchers from across a wide variety of disciplines from North America, Europe, Asia, and Oceania. This Special Topic section forms the second of the two issues dedicated to original contributions covering both fundamental physicochemical aspects of microfluidics and nanofluidics as well as their applications to the miniaturization of chemical and biological systems that were presented at the conference.