Molecular Switches :: essays research papers fc

     We live in the technology age. Nearly everyone in America has a information processing system or at least access to one. How big ar the computers you ar used to? Most are about 7" by 17" by 17". Thats a lot of space. These cumbersome units willing soon be replaced by something smaller. Much smaller, were talking about computers establish on lone molecules. As far off as this sounds, scientists are already making significant inraods into researching the feasability of this.     Our present technology is composed of solidness microelectronics based upon semiconductors. In the past few years, scientists have do 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 announced 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 abundant blocking groups at each end of the threaded           molecule." (Scientific American)The researchers linked legion(predicate) of these switches and came up with a rudimentary AND gate. An AND gate is a device which preforms a basic logic function. As much of an achievement as this was, it was solo a baby quantity. This million-moleculed switch was too large to be helpful and could only be used once.      In 1999, researchers at Yale University created molecular computer memory out of just one molecule. This is thought to be the "last step down in size" of technology because smaller units are not economical. The memory was created through a process called "self-assembly". "Self-assembly" is where computer engineers "grow" part and interconnections with chemicals. (Physics News Update, 1999) This unity molecule memory is better than the conventional atomic number 14 memory (DRAM) because the it live around one million times longer.            "With the single molecule memory, all a general-purpose           ultimate molecular computer needs now is a reversible single           molecule switch," says vibrating reed (the head researcher of the           team.) "I anticipate we will see a demonstration of one very           soon." (Yale, 1999)Reed was correct. Within a year, Cees Dekker and his colleagues at Delft University of Technology in the Netherlands had produced the first single molecule transistor.