Microfluidic systems can be designed to obtain and process measurements from small volumes of complex fluids with efficiency and speed,and without the need for an expert operator; this unique set of capabilities is precisely what is needed to create portable point-of-care (POC) medical diagnostic systems1,2. Fortunately for the microfluidics field, the military has always had a need to practise medicine in challenging and resource-limited environments, and so has long been trying to acquire robust medical technologies that add an absolute minimum to the burden of those people and machines transporting them. It was for this reason that microfluidics research in the United States was given a great boost in the 1990s by funding from the US Defense Advanced Research Projects Agency (DARPA). The technologies developed with DARPA’s support (for examples, see www.darpa.mil/MTO/mFlumes) have the characteristics needed for delivering appropriate medical diagnostics to the world’s poorest people. Today, the potential of microfluidic technologies to enhance the decentralization of medical testing is becoming accepted as one element in the next stage in the evolution of healthcare. Thanks to an upsurge in interest in (and funding of) healthcare in the developing world, combined with a slow pace of change in the developed world, this new microfluidic diagnostic technology (MDT) may be adopted first for civilian healthcare in the developing world. Some initial steps towards designing appropriate microfluidic diagnostic systems are described here.

stable gas/liquid separation method with a PTFE membrane was developed by arranging a fluidic network in three dimensions to achieve almost zero dead volume at the gas/liquid extraction part