New transparent insulating film could enable energy-efficient displays

November 9, 2009
In his Johns Hopkins materials science lab, Professor Howard E. Katz adjusts probes used for testing electronic devices. Credit: Will Kirk/JHU

Johns Hopkins materials scientists have found a new use for a chemical compound that has traditionally been viewed as an electrical conductor, a substance that allows electricity to flow through it. By orienting the compound in a different way, the researchers have turned it into a thin film insulator, which instead blocks the flow of electricity, but can induce large electric currents elsewhere. The material, called solution-deposited beta-alumina, could have important applications in transistor technology and in devices such as electronic books.

The discovery is described in the November issue of the journal Nature Materials and appears in an early online edition.

"This form of sodium beta-alumina has some very useful characteristics," said Howard E. Katz, a professor of materials science and engineering who supervised the research team. "The material is produced in a liquid state, which means it can easily be deposited onto a surface in a precise pattern for the formation of printed circuits. But when it's heated, it forms a solid, thin transparent film. In addition, it allows us to operate at low voltages, meaning it requires less power to induce useful current. That means its applications could operate with smaller batteries or be connected to a battery instead of a wall outlet."

The transparency and thinness of the material (the hardened film is only on the order of 100 atoms thick) make it ideal for use in the increasingly popular e-book readers, which rely on see-through screens and portable power sources, Katz said. He added that possible transportation applications include instrument readouts that can be displayed in the windshield of an aircraft or a ground vehicle.

The emergence of sodium beta-alumina as an was a surprising development, Katz said. The compound, known for decades, has traditionally been used to conduct electricity and for this reason has been considered as a possible battery component. The material allows charged particles to flow easily parallel to a two-dimensional plane formed within its distinct atomic crystalline arrangement. "But we found that current does not flow nearly as easily perpendicular to the planes, or in unoriented material," Katz said. "The material acts as an insulator instead of a conductor. Our team was the first to exploit this discovery."

The Johns Hopkins researchers developed a method of processing sodium beta-alumina in a way that makes use of this insulation behavior occurring in the form of a thin film. Working with the Johns Hopkins Technology Transfer staff, Katz's team has filed for international patent protection for their discovery.

More information:

Nature Materials Online Article: www.nature.com/nmat/journal/vaop/ncurrent/full/nmat2560.html
• A commentary about the Katz team's research: http://www.nature.com/nmat/journal/v8/n11/full/nmat2552.html

Source: Johns Hopkins University (news : web)

Explore further: Electric Jolt Triggers Release of Biomolecules, Nanoparticles

Related Stories

Electric Jolt Triggers Release of Biomolecules, Nanoparticles

September 11, 2006

Johns Hopkins researchers have devised a way to use a brief burst of electricity to release biomolecules and nanoparticles from a tiny gold launch pad. The technique could someday be used to dispense small amounts of medicine ...

Nanopatterns Regulate Electricity

February 8, 2007

Regular arrangements of sodium atoms make sodium cobalt oxide a perfect material for laptop batteries, an efficient cooling material and a superconductor. The concentration of sodium atoms in the material can vary and the ...

Recommended for you

Meet the high-performance single-molecule diode

July 29, 2015

A team of researchers from Berkeley Lab and Columbia University has passed a major milestone in molecular electronics with the creation of the world's highest-performance single-molecule diode. Working at Berkeley Lab's Molecular ...

Better together: graphene-nanotube hybrid switches

August 2, 2015

Graphene has been called a wonder material, capable of performing great and unusual material acrobatics. Boron nitride nanotubes are no slackers in the materials realm either, and can be engineered for physical and biological ...

0 comments

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.