A nanochip is an integrated circuit (IC) that is so small, in physical terms, that individual particles of matter play major roles. Miniaturization of electronic and computer components has always been a primary goal of engineers. The smaller an electronic system can be made, the more processing power can fit into a given physical volume, the less energy is required to run it, and the faster it can work (because distances among components are reduced, minimizing charge-carrier transit time). The earliest computers, built in the middle of the 20th century, used vacuum tube's for switching. These machines were so massive and bulky, and demanded so much electricity to operate, that they required buildings and power plants of their own. Today, such a computer can be placed inside a microscopic capsule. The trend toward miniaturization shows no sign of slowing until some limit is forced on the manufacturing process. The scale of this limit ultimately depends only on the structure of matter. Traditional methods of IC manufacture involve etching unwanted semiconductor material from a preexisting chip, in the same way a sculptor carves a statue. Futurists suggest that, rather than etching switches and logic gates into semiconductor material, chips ought to be mechanically assembled one molecule at a time. Some scientists believe ICs can be grown from biological seeds, just as a plant reproduces cells to create a defined structure such as a tree. Both of these processes involve nanotechnology, and would result in the greatest possible number of switches per unit volume of material substance. Nanochip is also the name of a nanotechnology research-and-development corporation based in San Jose, California as well as the trade name for a molecular biology workstation manufactured by Nanogen of San Diego, California