Conductive Materials
“In physics and electrical engineering, a conductor is a material which contains movable electric charges. In metallic conductors, such as copper or aluminum, the movable charged particles are electrons (see electrical conduction). Positive charges may also be mobile in the form of atoms in a lattice that are missing electrons (known as holes), or in the form of ions, such as in the electrolyte of a battery. Insulators are non-conducting materials with fewer mobile charges, which resist the flow of electric current.”
“All conductors contain electric charges which will move when an electric potential difference (measured in volts) is applied across separate points on the material. This flow of charge (measured in amperes) is what is meant by electric current. In most materials, the direct current is proportional to the voltage (as determined by Ohm's law), provided the temperature remains constant and the material remains in the same shape and state.”
“Most familiar conductors are metallic. Copper is the most common material used for electrical wiring. Silver is the best conductor, but is expensive. Because it does not corrode, gold is used for high-quality surface-to-surface contacts. However, there are also many non-metallic conductors, including graphite, solutions of salts, and all plasmas. There are even conductive polymers. See electrical conduction for more information on the physical mechanism for charge flow in materials.
Recent US Patents
11/23/2010
7,837,901
Electrically conductive polymer compositions
Hsu et of Dupont, Delaware, have developed conducting polymer materials consisting of an electrically conductive polymer or copolymer and an organic solvent wettable fluorinated acid polymer for electronic devices. Electrically conductive polymer materials are derived from thiophene, pyrrole, aniline and polycyclic heteroaromatic precursor monomers. Non-conductive polymers derived from alkenyl, alkynyl, arylene, and heteroarylene precursor monomers. The organic-solvent wettable fluorinated acid polymer is fluorinated or highly fluorinated and may be colloid-forming. Acidic groups include carboxylic acid groups, sulfonic acid groups, sulfonimide groups, phosphoric acid groups, phosphonic acid groups, and combinations thereof. (RDC 4/4/2011)