The cornerstone of microelectronics and MEMS, silicon-based manufacturing is taking over as a fundamental material in medicine. Research and laboratory diagnostic uses of biomolecular array technologies and microfluidics are well established. Novel sensor nanotechnologies are demonstrating features that make them an indispensable tool for the conquest of the post-genomic challenges, which present astronomical complexities in their requirement for multiplexed, real-time analyses. Controlled-release nanofluidic and microchip devices are under development as drug-delivery implants. Recently, nano-porous silicon has emerged as a material for medicine itself: it is biodegradable with tunable kinetics, eminently biocompatible, and provides suitable drug loading and release rates. Formed into micro-and nanoparticles of ‘designer’ size, shape and surface properties, nanoporous silicon is a particularly versatile material for the next generation of nanomedical therapeutic products.