From chip-in-a-lab to lab-on-a-chip: Basic advances surmount technology barriers

Lab-on-a-chip devices have held out the promise to revolutionise health-care by carrying out clinical tests in autonomous devices that perform all the functions of a diagnostic laboratory. However, the few tests that have been commercialised (blood glucose meters) are based on capillary action and do not involve sample preparation. The flow at small scales is laminar, and this results in a technological barrier for sample preparation in chip-based devices. In nature, this barrier is overcome by a transition to a turbulent flow at large scales. Our research work on triggering turbulence in small devices at low velocities using soft surfaces, as a means of significantly increasing mixing rates, will be discussed after an introduction to lab-on-a-chip devices and the transition to turbulence.