Silver ink prints electronics on flexible materials

Silver ink prints electronics on flexible materials Materials scientists from Illinois University have developed a reactive silver ink for printing high performance electronics on materials including flexible plastic, paper or fabric substrates.

The new ink is a transparent solution of silver acetate and ammonia: the silver remains dissolved in the solution until it is printed and the liquid evaporates, yielding conductive features.

“It dries and reacts quickly which allows us to immediately deposit silver as we print,” explains graduate student S Brett Walker.

The reactive ink is said to have several advantages over particle based inks. A batch takes minutes to mix whereas particle-based inks take several hours and multiple steps to prepare.

The reactive silver ink can print through 100nm nozzles said to be an order of magnitude smaller than particle-based inks. Moreover, its low viscosity makes it suitable for inkjet printing, direct ink writing or airbrush spraying over large, conformal areas.

“For printed electronics applications you need to be able to store the ink for several months because silver is expensive,” says Walker. “Since silver particles don’t actually form until the ink exits the nozzle and the ammonia evaporates, our ink remains stable for long periods – a rarity for finescale nozzle printing.”