New patterning technique produces faithful reproduction of grayscale images down to micrometer level

Jun 08, 2012
A scanning-electron micrograph of the ‘Lena’ image. © 2011 American Vacuum Society

In his 1959 lecture There's Plenty of Room at the Bottom, the US physicist Richard Feynman asked the question: “Why cannot we write the entire 24 volumes of the Encyclopaedia Britannica on the head of a pin?” Since then, scientists have made great advances in the nascent field of nanotechnology — and among them, the reading and writing of features at the atomic scale.

Current techniques for patterning features at the atomic scale, however, have been limited by their ability to replicate colors or grayscale information. Joel Yang at the A*STAR Institute of Materials Research and Engineering and co-workers have now developed a patterning technique that produces a faithful reproduction of grayscale images with accuracy down to tens of micrometers.

Conventional micro-patterning techniques typically build on halftone printing, whereby the brightness of the image is generated by varying the density of monochromatic elements. Yang’s technique considers these elements as ‘nanoposts’ — posts of only ten nanometers in size — that are arranged in one of 17 possible patterns or ‘shades’. It then produces faithful reproductions of grayscale images using these 17 shades in hand.

As a proof of principle, the researchers replicated the patterns of a test image (pictured) onto an area of 40 square micrometers. In the densest region, the separation between individual dots was a mere 10 nanometers.

The halftone technique had been used before to create grayscale optical micrographs. However, Yang and colleagues have now pushed the approach into the realm of electron microscopy: “Our technique utilizes an electron-beam-lithography method with one of the best resolutions, allowing us to create grayscale images that are highly miniaturized,” explains Yang. “The method should be useful for creating images that can be seen under an optical microscope and may open up new avenues to adding colors to images.”

Yang and his team envisioned several uses of the miniaturized images, for example, in anti-counterfeit features to nanophotonic devices. “But above all, these are striking images,” says Yang. Indeed, one of the — a 4000-fold miniaturization of M. C. Escher’s mezzotint Dewdrop — has won last year’s Grand Prize Award of the International Conference on Electron, Ion, and Photon Beam Technology and Nanofabrication (EIPBN) conference. "Winning that award was a thrilling experience especially as it was presented by a community of nanofabrication experts", says Yang. "One who stares enough into the screen of a scanning electron microscope would appreciate the intrigue and aesthetic beauty of these micrographs. It is rare to see a scanning-electron-microscope image of a photo-realistic person staring back at you from the nanoworld."

Explore further: Cooling with the coldest matter in the world

More information: Yang, J. K. W., et al. Miniaturization of grayscale images. Journal of Vacuum Science and Technology B 29, 06F313 (2011). dx.doi.org/10.1116/1.3660790

add to favorites email to friend print save as pdf

Related Stories

Are electron tweezers possible? Apparently so

Nov 09, 2011

(PhysOrg.com) -- Not to pick up electrons, but tweezers made of electrons. A recent paper by researchers from the National Institute of Standards and Technology (NIST) and the University of Virginia (UVA) demonstrates that ...

What lies beneath: Mapping hidden nanostructures

Feb 10, 2012

The ability to diagnose and predict the properties of materials is vital, particularly in the expanding field of nanotechnology. Electron and atom-probe microscopy can categorize atoms in thin sheets of material, ...

Recommended for you

Cooling with the coldest matter in the world

Nov 24, 2014

Physicists at the University of Basel have developed a new cooling technique for mechanical quantum systems. Using an ultracold atomic gas, the vibrations of a membrane were cooled down to less than 1 degree ...

Magnetic fields and lasers elicit graphene secret

Nov 24, 2014

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have studied the dynamics of electrons from the "wonder material" graphene in a magnetic field for the first time. This led to the discovery of ...

New 2-D quantum materials for nanoelectronics

Nov 21, 2014

Researchers at MIT say they have carried out a theoretical analysis showing that a family of two-dimensional materials exhibits exotic quantum properties that may enable a new type of nanoscale electronics.

User comments : 0

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.