The ability to perform laboratory operations on a small scale using miniaturized (lab-on-a-chip) devices is very appealing. Small volumes reduce the time taken to synthesize and analyse a product; the unique behaviour of liquids at the microscale allows greater control of molecular concentrations and interactions; and reagent costs and the amount of chemical waste can be much reduced. Compact devices also allow samples to be analysed at the point of need rather than a centralized laboratory.

Initially, however, pioneers of the field asked in Chimia whether their ideas about miniaturization would be “next century's technology or just a fashionable craze”. The advantages are compelling, but designing and making devices of reduced size that operate effectively is challenging. The pioneers recognized the huge financial input and research effort needed to realize the full potential of the concept.

Now, well into that next century, it is clear that labs on chips are here to stay. Physicists and engineers are creating exciting functionality, and are starting to construct highly integrated compact devices. Chemists are using such tools to synthesize new molecules and materials, and biologists are using them to study complex cellular processes. Furthermore, labs on chips offer point-of-care diagnostic abilities that could revolutionize medicine. Such devices may find uses in other areas, including a range of industrial applications and environmental monitoring. Commercial exploitation has been slow, but is gaining pace, with some products now on the market. A technology for this century? The signs are looking good.

In this Insight, we present a collection of topical Reviews that discuss the history, design, application and future of lab-on-a-chip technologies, focusing on microfluidic flow devices. We hope you enjoy it.

We are pleased to acknowledge the financial support of Agilent Technologies in producing this Insight. As always, Nature carries sole responsibility for editorial content and peer review.