U.S. scientists say they've developed a silver nanoparticle ink that can create flexible, stretchable and spanning microelectrodes.

University of Illinois Professor Jennifer Lewis and colleagues said such printed microelectrodes can withstand repeated bending and stretching with minimal change in their electrical properties.

"Unlike inkjet or screen printing, our approach enables the microelectrodes to be printed out-of-plane, allowing them to directly cross pre-existing patterned features through the formation of spanning arches," Lewis said. "Typically, insulating layers or bypass electrode arrays are required in conventional layouts."

When printed, the silver nanoparticles are not yet bonded together, the scientists said. The bonding process occurs when the printed structure is heated to 150 degrees Celsius or higher. During thermal annealing, the nanoparticles fuse into an interconnected structure and, since only modest processing temperatures are required, the printed features are compatible with flexible, organic substrates.

The research that included Bok Yeop Ahn, Eric Duoss and Professors Ralph Nuzzo and John Rogers, appears in the online journal Science Express.