Molecular Switches :: essays research papers fc

     We last in the technology age. Nearly everyone in America has a estimator or at least access to one. How big be the computers you are used to? Most are ab bulge out 7" by 17" by 17". Thats a lot of space. These cumbersome units will shortly be replaced by something smaller. Much smaller, were talking about computers ground on lone scintillas. As far off as this sounds, scientists are already making significant inraods into researching the feasability of this.     Our present technology is composed of solid-state microelectronics based upon semiconductors. In the past few years, scientists have make momentus discoveries. These advances were in molecular scale electronics, which is based on the idea that molecules can be made into transistors, diodes, conductors, and other components of microcircuits. (Scientific American) Last July, researchers from Hewlitt-Packard and the University of California at Los Angeles announce d that they had made an electronic switch of a layer of several million molecules and rotaxane.           "Rotaxane is a pseudorotaxane. A pseudorotaxane is a           compound consisting of cyclic moles threaded by a linear           molecule. It also has no covalant interaction. In rotaxane,           there are bulky cylinder block groups at each end of the threaded           molecule." (Scientific American)The researchers linked many of these switches and came up with a rudimentary AND gate. An AND gate is a device which preforms a canonical logic function. As much of an achievement as this was, it was only when a baby step. This million-moleculed switch was too large to be useful and could only be used once.      In 1999, researchers at Yale Universi ty created molecular stock out of just one molecule. This is thought to be the "last step passel in size" of technology because smaller units are not economical. The remembering was created through a process called "self-assembly". "Self-assembly" is where computer engineers "grow" parts and interconnections with chemicals. (Physics give-and-take Update, 1999) This single molecule memory is better than the conventional silicon memory (DRAM) because the it live around one million times longer.            "With the single molecule memory, all a general-purpose           ultimate molecular computer necessitate now is a reversible single           molecule switch," says Reed (the forefront researcher of the           team.) "I anticipate we will see a intro of one very            soon." (Yale, 1999)Reed was correct. Within a year, Cees Dekker and his colleagues at Delft University of engineering in the Netherlands had produced the first single molecule transistor.