INTRINSICALLY CONDUCTING RUBBERS: TOWARD MICRO APPLICATIONS

More than three decades after the major breakthrough in the efforts to develop intrinsic electric conductivity in conjugated polymers, which culminated in the year 2000 Nobel Prize for Shirakawa et al., conducting plastics hold the promise of providing a cost effective and unique alternative material solution for applications ranging from consumer electronics to optoelectronics, solar cells, lighting, memory, and a host of new photonic applications. It would not be an exaggeration to mention conducting polymers as the materials for the next century. The notion of conjugation as a pre-condition for a polymer to be made intrinsically conducting was challenged when a conjugated polymer such as natural rubber was doped to increase its electrical conductivity by more than 10 orders in magnitude. This discovery by Thakur et al., triggered a spate of investigations on the phenomenon and mechanism of conduction in nonconjugated polymers such as Elastomers. The discovery that rubbers could be doped like conjugated polymers raised the hope of finding extremely different micro applications hitherto unknown for natural rubber as well as synthetic rubbers. Investigations point toward the possibility of conducting rubbers, unlike the conjugated polymers having easy processability and cost effectiveness, finding wide applications in organic electronics and photonic applications. A critique of the early and current efforts in developing intrinsic electric conductivity in natural rubber as well as synthetic elastomers in the context of the investigations made by the authors in this direction is reviewed and presented.