The lab on a chip

Using the example of open-tubular liquid chromatography, the authors demonstrate improved performance, cheap and simple production and miniaturisation through microengineering. Improved performance can result from efficient heat transfer (capillary electrophoresis and PCR), reduced diffusion path lengths (chromatography and coupled chemical reactions) and from the ability to produce devices with optimised geometry. Microengineering can also allow method integration, leading to the concept of an entire analytical facility on a single chip. Given the early promise, it is likely that these devices, or less complex microengineered structures which couple chemical or biochemical sensors with suitable sample processing packages, will become important tools in industrial, environmental and clinical measurement