Scientific discoveries Essay Example | Topics and Well Written Essays - 500 words

Scientific discoveries - Essay Example Molecular electronics face two types of challenges. The first challenge is building molecular structures that act as switches and the second challenge is combining these molecules into a complex circuit in order that they are able to perform a specific function. These two tasks demand reproducible organic molecular conductors and insulators. Polyphenylene based molecules besides carbon nanotubes have been considered as possible candidate molecules capable of these tasks (3). In October 2009 a team of researchers led by bio-designer N. J. Tao reported success in the development of key electrical component of the diode on a phenomenally tiny molecular scale, namely the single-molecule diode. (4). Diodes constitute critical components for a wide range of applications that include power conversion equipment, radios, logic gates, photodetecters and light emitting devices. In all these applications diodes make up the components that permit current to flow in one direction, but not in the other direction in an electrical circuit. To bring this specific function down to the level of a molecule, the molecule should be physically asymmetrical, where one end of the molecule has the capacity to form a covalent bond with the negatively charged anode terminal and the other end capable of bonding with the positively charged cathode terminal. A symmetrical molecule allows current to flow in both directions, which is similar to an ordinary resistor. On the other hand an asymmetrical molecule allows current to flow in only direction similar to a diode, which is the more important and difficult component to replicate. With the size of a transistor in the field of electronics nearing a few te n nanometers or about twenty times larger than a molecule, the development of a molecular diode is exciting. (5). The Tao led research team studied conjugated molecules for the purpose of developing a molecular diode. In conjugated molecules the atoms are stuck together by alternating