ENTERING THE NEXT DIMENSION: Microfabrication techniques, including printing patterns on cylinders, construct 3-D objects

WE LIVE IN A THREE-DIMENsional world, but you'd never know it from conventional microfabrication techniques, which are intrinsically planar. With those techniques, 3-D objects can be made only by layering parallel planes. "A real challenge for microfabrication is to see if one can develop new tools and new procedures that make it possible to do new kinds of micron-scale fabrication in three dimensions," says George M. Whitesides, professor of chemistry at Harvard University. "We're exploring a number of techniques for making 3-D microstructures that circumvent the limitations of planar methods," he notes. Whitesides' group has developed several methods for making these small structures. The group has dubbed one of the techniques "microorigami" after the Japanese art of paper folding. Three-dimensional SCIENCE & TECHNOLOGY objects are formed by folding a planar metal structure with bendable parts { J. Phys. Chem. B , 105 , 347 (2001)}. The metal structure is made by stamping hexadecanethiol, which forms a ...