Particle-free silver ink prints small, high-performance electronics

Jan 13, 2012
Reactive silver ink is airbrushed onto a thin, stretchy plastic film to make a flexible silver electrode. Credit: S. Brett Walker

University of Illinois materials scientists have developed a new reactive silver ink for printing high-performance electronics on ubiquitous, low-cost materials such as flexible plastic, paper or fabric substrates.

Jennifer Lewis, the Hans Thurnauer Professor of Materials Science and Engineering, and graduate student S. Brett Walker described the new in the .

"We are really excited about the wide applicability and excellent of this new silver ink," said Lewis, the director of the Frederick Seitz Materials Research Laboratory at the U. of I.

Electronics printed on low-cost, hold promise for antennas, batteries, sensors, solar energy, wearable devices and more. Most conductive inks rely on tiny 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," Walker said.

The reactive ink has several advantages over particle-based inks. It is much faster to make: A batch takes minutes to mix, according to Walker, whereas particle-based inks take several hours and multiple steps to prepare. The ink also is stable for several weeks.

The reactive silver ink also can print through 100-nanometer nozzles, an order of magnitude smaller than particle-based inks, an important feature for printed microelectronics. Moreover, the ink's low viscosity makes it suitable for inkjet printing, direct ink writing or airbrush spraying over large, conformal areas.

"For printed , you need to be able to store the ink for several months because silver is expensive," Walker said. "Since silver particles don't actually form until the ink exits the nozzle and the ammonia evaporates, our ink remains stable for very long periods. For fine-scale nozzle printing, that's a rarity."

The reactive silver ink boasts yet one more key advantage: a low processing temperature. Metallic inks typically need to be heated to achieve bulk conductivity through a process called annealing. The annealing temperatures for many particle-based inks are too high for many inexpensive plastics or paper. By contrast, the reactive silver ink exhibits an electrical conductivity approaching that of pure silver upon annealing at 90 degrees Celsius.

"We are now focused on patterning large-area transparent conductive surfaces using this reactive ink," said Lewis, who also is affiliated with the Beckman Institute for Advanced Science and Technology, the Micro and Nanotechnology Lab and the department of chemical and biomolecular engineering at the U. of I.

Explore further: Artificial muscles get graphene boost

More information: J. Am. Chem. Soc., Article ASAP DOI: 10.1021/ja209267c

Related Stories

Researchers create rollerball-pen ink to draw circuits

Jun 28, 2011

(PhysOrg.com) -- Two professors from the University of Illinois; one specializing in materials science, the other in electrical engineering, have combined their talents to take the idea of printing circuits ...

Recommended for you

Graphene and diamonds prove a slippery combination

5 hours ago

Scientists at the U.S. Department of Energy's Argonne National Laboratory have found a way to use tiny diamonds and graphene to give friction the slip, creating a new material combination that demonstrates ...

Artificial muscles get graphene boost

May 22, 2015

Researchers in South Korea have developed an electrode consisting of a single-atom-thick layer of carbon to help make more durable artificial muscles.

How to make continuous rolls of graphene

May 21, 2015

Graphene is a material with a host of potential applications, including in flexible light sources, solar panels that could be integrated into windows, and membranes to desalinate and purify water. But all ...

Carbon nanothreads from compressed benzene

May 20, 2015

A new carbon nanomaterial – the thinnest possible one-dimensional thread that still retains a diamond-like structure – was created by the controlled, slow compression and decompression of benzene. The ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

kaasinees
0.3 / 5 (23) Jan 13, 2012
silver ink that exists without silver particles?? wow impressive.
Valentiinro
5 / 5 (5) Jan 13, 2012
They mean that it's a solution, rather than a suspension, kaasinees.
That description is pretty funny though.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.