Researchers tout super-stretchy electronic material

Researchers have created ‘super-stretchy’ integrated circuits that could be used in intelligent surfaces for curved objects, or in movable parts such as the joints of a robot’s arm.

The circuits can be stretched by up to 70 percent without any degradation in their mechanical or electronic properties, according to the University of Tokyo researchers.

Stretchable electronics is a current challenge for material engineers, particularly for its application in large-area electronics such as bendable and rollable displays.

While soft materials currently tend to be more mechanically robust than rigid materials, stretchable electronics tend to exhibit poorer electronic properties such as performance, controllability and stability.

“Stretchability is an entirely different concept from the miniaturisation trend currently pursued by conventional electronics and has the potential to provide exciting opportunities,” said Takao Someya, lead researcher and Associate Professor at the University of Tokyo’s Quantum Phase Electronics Center.

“Large-area, flexible sensors and actuators are another emerging frontier, [but] although these achievements represent valuable advances, the utility of flexible electronics is limited to nearly flat substrates,” he told iTnews.

“Stretchable electronics can cover arbitrary curved surfaces and movable parts such as the joints of a robot’s arm, thereby significantly expanding the area of utilization of these electronics.”

Someya’s integrated circuits use a newly-developed carbon nanotube-elastomer composite material as a conducting dopant, which boasts a measured conductivity of 57 S/cm.

Researchers claim the conductivity of the new polymer to be two orders of magnitude greater than the conductivity value of previously reported single-walled nanotube (SWNT) composite polymers.

“Carbon-nanotube-based conducting materials have been produced previously [but] their conductivities are very low,” Someya said.

“One can say that the elastic conductors developed in this study are the world’s first chemically stable, highly conductive elastomers,” he said.

Researchers suggest that the stretchable circuits could enable ambient electronics, in which a multitude of devices such as sensor networks could be used to enhance aspects of security, safety, and convenience in daily life.

The technology also could by integrated with pressure sensors to yield a ‘rubber-like artificial skin’, or with an array of actuators to change the feel of a surface.

“This is an important step toward the production of intelligent surfaces that can be used as friendly human-electronics interfaces,” Someya said.

“In the future, such intelligent surfaces will be able to interact with people, objects, and the environment in new ways.”