Since the early 1990s, the concepts of miniaturization have been applied to chemical and biological problems. Of special interest has been the development of lab-on-a-chip techniques, using microfluidics, and driven by a need to accomplish rapid analysis of the small sample volumes needed in drug discovery, high-throughput screening, genomics and medical diagnostics. However, the appeal of microfluidic technology lies in the fact that physical processes can be more easily controlled, accelerated and exploited when instrument dimensions are miniaturised.

More recently, some scientists have begun to generate microdroplets within microfluidic structures. These droplets have vanishingly small volumes and hold much promise as tools in high-throughput analysis. Robert Wootton and Andrew deMello report on recent advances in this area and ponder the extraordinary potential of microdroplets as analytical tools.