But often the device simply acts as the electronic equivalent of an on-off switch. When on, it completes a circuit and lets current flow; when off, it breaks the electrical path. • lone transistors suck- strength in numbers • Transistors are possible because the semiconductors they’re built from—elements like silicon and germanium—have one strange and very useful property: They carry electricity better than insulators, such as glass, but not as well as conductors—aluminum for example. Scientists can push a semiconductor’s conductivity one way or the other by doping—adding small amounts of impurities. (Arsenic and boron are two of the commonly used elements. ) “When you dope silicon you make it act differently,” says Shahidi. “It can act like an insulator or as a metal. ” Doping specific areas of a semiconductor in different ways is what creates a transistor enables its switching action. • Experts have been working for many years to understand how to work with electronic material produced on an increasingly small scale.
In the emerging field of nano-science and nano-technologies it is important for scientists to be able to control the structure and bonding of molecules that are used in creating small scale electronic components for products such as computers. Scientists have succeeded in imaging and forming a unique bond between a single gold atom and a single organic molecule called a pentacene. They managed to bind the atom to the pentacene and take images of rearrangements of the electrons participating in the formation of the chemical bond.