August 20, 2008 Scientists at the University of Tokyo have created a material with the texture and flexibility of rubber, but possessing more than 570 times the electrical conductivity. Made by grinding carbon nanotubes with an ionic liquid and adding it to rubber, the material could be used to make intelligent steering wheels and mattresses, stretchable television displays, or sensitive e-skin for robots.
Tsuyoshi Sekitani, a research associate on the team, said the material could be used to create heat and pressure sensitive devices that interact with people on a more intuitive level. Steering wheels could analyse perspiration, body temperature and other bodily signs to gauge the fitness of the driver; mattresses could tilt the bed when they detect parts of the body are under constant pressure; and the team believes it will be possible one day to incorporate the material into human bodies.
"Objects that come into contact with humans are often not square or flat. We believe interfaces between humans and electronics should be soft," Sekitani said.
While metal wires have a stretching threshold of one to two percent, the rubber can be stretched by 38% without suffering a significant change in conductivity. Taking it to its limits, it can be stretched up to 2.3 times its original size, losing roughly half of its conductivity at the maximum extension. If used as wiring, the material can make elastic integrated circuits which can be stretched by up to 1.7 times their original length with no mechanical damage or change in conductivity.
Another exciting potential application is “e-skin” for robots. The scientists claim the material will feed robots the sensory information they require to comfortably move among us and complete whatever tasks we may set – doing housework, handling children, eliminating John Connor, etc. The University of Tokyo team aims to put the elastic conductor to practical use within the next several years.