I started playing around with electronics when tubes were the device of choice for home and car electronics. Over the last 50 years electronics have gotten much smaller – my Kenwood TH-F6A HT is about the size of a deck of cards and in addition to transmitting on three bands it is capable of AM, SSB and FM reception on frequencies from 0.01 to 1300 MHz! Smartphones combine an amazing amount of computing and communications power in a tiny package. Can electronic circuits get even smaller? The answer, as you probably guessed, is yes.
Scientists are now working on single molecule electronics. One of the problems with these nanoscopic devices is connecting to them. Researchers have made a breakthrough that could reduce common electronic circuits in computers, smart phones, audio players and other devices to the size of a grain of sand. Yuji Okawa and colleagues write that the "key to single-molecule electronics is connecting functional molecules to each other using conductive nanowires. This involves two issues: how to create conductive nanowires at designated positions, and how to ensure chemical bonding between the nanowires and functional molecules."
The scientists demonstrated a method that uses the tip of a scanning tunneling microscope to "jump-start" the formation of a molecule chain. The chain then spontaneously chemically bonds with other molecular components in the circuit under construction, forming a "wire." The scientists say their technique "will enable us to develop cheaper, higher-performance, and more ecological alternatives to conventional silicon-based devices."
Information from an American Chemical Society public release. For technical details, see the Chemical Wiring and Soldering toward All-Molecule Electronic Circuitry.
