DNA drives design principles for lighter, thinner optical displays

June 26, 2018 by Amanda Morris, Northwestern University
Credit: CC0 Public Domain

DNA is certainly the basis of life. Soon it might also be the basis of your electronic devices.

A Northwestern University team has developed a new set of design principles for making photonic crystals akin to the ones that are typically used in computer, television and smartphone displays. By using synthetic DNA to assemble particles into crystalline lattices, the researchers have opened the door for much lighter and thinner displays compared to what is currently available.

"Most people look at a laptop display every day, but few people understand what they are made of and why," said George Schatz, Charles E. and Emma H. Morrison Professor of Chemistry in Northwestern's Weinberg College of Arts and Sciences. "One component of the display is the back-reflector, a mirror-like device that directs the light emitted by the LCD to the viewer. These reflectors are made using layered polymers that are much thicker and heavier than our crystals."

Northwestern's approach not only replaces these polymers with gold nanocrystals but also spaces them apart to leave air among them. The result is a lighter, more compact, precisely designed and reconfigurable structure that is still highly reflective.

The research was published online yesterday in the Proceedings of the National Academy of Sciences (PNAS). Schatz and Chad Mirkin, the director of Northwestern's International Institute for Nanotechnology and the George B. Rathmann Professor of Chemistry, served as the paper's co-corresponding authors.

Although DNA is almost always associated with living organisms—from simple bacteria to complex humans—the DNA used in the study is chemically synthesized and manipulated rather than derived from living cells. In 1996, Mirkin invented ways to link synthetic DNA to to produce new materials not found in nature—to essentially use the "blueprint of life" to program their formation. These structures have become the basis for more than 1,800 globally used products, primarily in the life sciences.

Then, in 2008, Mirkin and Schatz collaborated to make crystals from particles linked by DNA. By attaching strands of synthetic DNA to tiny gold spheres, the duo found they could build three-dimensional crystalline structures. Changing the DNA strand's sequence of Gs, As, Ts and Cs changes the shape of the crystalline structure, allowing the researchers to arrange the particles differently in space. More than 500 crystal types, spanning more than 30 different crystal symmetries have been made using this approach, making it a powerful and fundamentally new way to program the formation of crystalline matter.

Despite making sophisticated advances with this work since 2008, Mirkin and Schatz did not initially realize that the crystal lattices they made in the laboratory had similar to the polymer layers found in device displays.

"Through computer modeling, we realized by accident that the crystalline materials with gold nanoparticles had properties that we missed earlier in the work," Schatz said. "We then optimized the optical properties using computations, and these demonstrated that the non-touching metal spheres could, in some cases, be better than the touching polymer spheres."

After making the crystals in the laboratory, Mirkin's and Schatz's teams measured the crystals' optical properties to find that their computational modeling was indeed correct. Although they only tested the crystalline lattice's reflective nature in the current PNAS paper, the method could lead to many types of functional "designer" materials using DNA-driven self-assembly.

"The generality of the approach and the design rules are quite extraordinary and independent of particle composition," Mirkin said. "This takes what we initially conceived in the 1990s to entirely new heights."

Explore further: DNA is blueprint, contractor and construction worker for new structures

More information: Lin Sun et al. Design principles for photonic crystals based on plasmonic nanoparticle superlattices, Proceedings of the National Academy of Sciences (2018). DOI: 10.1073/pnas.1800106115

Related Stories

Chameleon-inspired nanolaser changes colors

June 20, 2018

As a chameleon shifts its color from turquoise to pink to orange to green, nature's design principles are at play. Complex nano-mechanics are quietly and effortlessly working to camouflage the lizard's skin to match its environment.

Building crystalline materials from nanoparticles and DNA

October 13, 2011

Nature is a master builder. Using a bottom-up approach, nature takes tiny atoms and, through chemical bonding, makes crystalline materials, like diamonds, silicon and even table salt. In all of them, the properties of the ...

Most complex nanoparticle crystal ever made by design

March 2, 2017

The most complex crystal designed and built from nanoparticles has been reported by researchers at Northwestern University and confirmed by researchers at the University of Michigan. The work demonstrates that some of nature's ...

Recommended for you

Solving mazes with single-molecule DNA navigators

November 16, 2018

The field of intelligent nanorobotics is based on the great promise of molecular devices with information processing capabilities. In a new study that supports the trend of DNA-based information carriers, scientists have ...

A way to make batteries almost any shape desired

November 16, 2018

A team of researchers from Korea Advanced Institute of Science and Technology, Harvard University and Korea Research Institute of Chemical Technology has developed a way to make batteries in almost any shape that can be imagined. ...

Graphene flickers at 400Hz in 2500ppi displays

November 16, 2018

With virtual reality (VR) sizzling in every electronic fair, there is a need for displays with higher resolution, frame rates and power efficiency. Now, a joint collaboration of researchers from SCALE Nanotech, Graphenea ...

'Smart skin' simplifies spotting strain in structures

November 15, 2018

Thanks to one peculiar characteristic of carbon nanotubes, engineers will soon be able to measure the accumulated strain in an airplane, a bridge or a pipeline – or just about anything – over the entire surface or down ...

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.