Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


High-Fidelity Patterns Form Spontaneously When Solvent Evaporates


Resembling neatly stacked rows of driftwood abandoned by receding tides, particles left by a confined, evaporating droplet can create beautiful and complex patterns. The natural, pattern-forming process could find use in fields such as nanotechnology and optoelectronics.

"A lot of work in nanotechnology has been directed toward the bottom-up imposition of patterns onto materials," said Steve Granick, a professor of materials science, chemistry and physics at the University of Illinois at Urbana-Champaign. "We found that beautiful patterns of high fidelity and regularity could form naturally and spontaneously, simply by allowing a drop to evaporate in a confined geometry."

Granick and former postdoctoral research associate Zhiqun Lin (now a professor of materials science at Iowa State University) describe their work in a paper that has been accepted for publication in the Journal of the American Chemical Society, and posted on its Web site. Funding was provided by the U.S. Department of Energy.

To produce the patterns, Granick and Lin began by gluing two small mica sheets to cylindrical mounts. With the cylinders at right angles, a droplet of volatile solution containing small polymer chains was inserted between the curved mica sheets. The sheets were then brought into contact and left undisturbed until evaporation was complete.

Because evaporation in this geometry is restricted to the edge of the droplet, the process results in hundreds of concentric rings with regular spacing, very much resembling a miniature archery target. Each ring - composed of polymer chains abandoned as the solvent receded - is several nanometers high and several microns wide.

The droplet evaporates in a jerky, stick-slip fashion, said Granick, who also is a researcher at the Frederick Seitz Materials Research Laboratory and at the Beckman Institute for Advanced Science and Technology.

"While the droplet is sticking to the surface, a ring of polymer is deposited," he said. "As evaporation continues, tension builds in the droplet. Eventually the droplet jerks to a new position, the tension is temporarily relieved, and another ring is deposited."

The simple evaporative process could be used to form patterns with many other materials, such as electrically conducting polymers, nanoparticles and proteins. Pattern formation could be controlled by altering the size of the material, changing the solvent, or modifying the surfaces.

"The pattern emerges spontaneously from the geometry in which we put the droplet," Granick said. "This means we could make other kinds of patterns by using different geometries or surfaces with tailored wettability."

James E. Kloeppel | News Bureau
Further information:

More articles from Materials Sciences:

nachricht How nanoscience will improve our health and lives in the coming years
27.10.2016 | University of California - Los Angeles

nachricht 3-D-printed structures shrink when heated
26.10.2016 | Massachusetts Institute of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>