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About This Technology

Industry continuously strives to make products that are smaller and lighter, are lower cost, yet have increased functionality. Micromachining is the ability to make components and devices whose features measure in the tens to hundreds of microns and, in some cases, even submicrons. Microelectromechanical systems, or MEMS, are a class of devices or microsystems produced using micromachining technology. Initially, scientists borrowed lithography techniques for making two-dimensional integrated circuits from the electronics industry to micromachine simple three-dimensional cavities and freestanding membranes and cantilevers for sensor applications. Not only are microsensors smaller than conventional sensors, a characteristic that allows more functions in the same space, but they can also respond more quickly and more accurately, because of the smaller distances in use. Moreover, producing them in large batches is inexpensive. The extension of lithography methods and development of new micromachining techniques have allowed the production of freely moving micromechanical parts.

The biggest current market for micromachining is in sensors, from solid-state pressure sensors to automotive accelerometers. Also, the manufacture of many components in existing instruments and office equipment—such as the tiny nozzles in ink-jet printer heads, slider components for hard-disk drives, and the tips for atomic-force microscopes—relies on micromachining techniques. Micromachining has enabled cell phones to incorporate multiple functions, and MEMS-based microphones are quickly replacing traditional microphones in cell phones.

Micromachining is producing fluidic channels for DNA chips, allowing massive parallelism for high-throughput screening techniques, and is reducing some analytical instruments to handheld size.In the longer term, micromachining will contribute to implantable drug-delivery systems and other biomedical devices; tiny mechanical parts may allow the emergence of microrobots that can perform work in very small spaces, including those in the human body.

Almost every industry will enjoy the benefits of micromachining, particularly the information technology, telecommunications, automotive, and health-care industries. The relatively low cost of microsensors—$1 to $20 each—will also allow manufacturers to use sensors in many more products than they can now including consumer-electronics products, home appliances, toys, and products for home health care. These sensors and other micromechanical devices will eventually have remote powering and connect to the Internet, allowing remote interrogation of industrial sensors, connection of home health-care devices to a physician's office, and remote control of in vitro biomedical devices. Some time after 2010, industry may have to contend with another revolution: molecular manufacturing, or nanotechnology.