Ink enables electronics to be printed on flexible substrates

According to a statement, electronics printed on low-cost, flexible materials hold promise for antennas, batteries, sensors, solar energy or wearable devices.

Most conductive inks rely on metal particles suspended in the ink. 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,’ said graduate student S Brett Walker.

The reactive ink is said to have several advantages over particle-based inks. It is much faster to make, with a batch taking minutes to mix, according to Walker, whereas particle-based inks take several hours and multiple steps to prepare. The ink is also stable for several weeks.

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