Recent years have seen significant advances in the properties achieved by both these materials, and so researchers have begun to blend these materials into nanocomposites that access the properties of both materials.
The heated probe of an atomic force microscope melts a nanoparticle-polymer composite enabling it to flow onto a surface. The nanocomposite can be used as-is or the nanoparticles released with an oxygen plasma. (Image courtesy of UIUC and NRL.) Forming these nanocomposites into structures has been tricky since each nanocomposite would require a particular set of solvents or a particular surface coating.
To solve this problem, the NRL and UIUC team developed a generic means for depositing many nanocomposites on multiple surfaces with nanoscale precision. Metal nanoparticles that were conducting, tiny magnetic nanoparticles, and nanoparticles that glowed, were all deposited using this one technique.
The technique builds on previous work using atomic force microscopy (AFM) probes as pens to produce nanometer-scale patterns. The polymer-nanocomposite blend is coated onto the probe. When the probe is heated, it acts like a miniature soldering iron to deposit the nanocomposite. "This technique greatly simplifies nanocomposite deposition," said Paul E. Sheehan, head of the Surface Nanoscience and Sensor Technology Section at NRL in Washington, D.C. "No longer do you have to spend half a year tweaking the chemistry of the surface or nanocomposite to achieve deposition."
The technique also solves a common problem when depositing soft materials like polymers and nanocomposites. The solvents and patterning procedures for depositing soft materials can damage any soft material already deposited. Consequently, it can be quite difficult to deposit many different such materials. "Our ability to control nanometer-scale heat sources allows local thermal processing of these nanocomposites," says William King, Kritzer Faculty Scholar in the Department of Mechanical Science and Engineering at the University of Illinois Urbana-Champaign. This opens a door to the direct writing of highly complex structures.
Although the nanoparticles were typically dispersed throughout the nanocomposite, the researchers found that by adjusting the nanoparticle chemistry they could force the nanoparticles into alignment. "With the right chemistry, the forces in the polymer will guide the nanoparticles into thin rows." Rows of nanoparticles less than 10 nm wide were written, narrower than any other direct write technique. The string of magnetic nanoparticles should be useful for studying magnetic interactions on the smallest scales. "Combining with our nanolithographic technique these tiny magnetic nanostructures can be added to current electronic or MEMS devices to enhance their capabilities." says Woo Kyung Lee.
"These capabilities and those of the other nanocomposites may find novel applications from microelectronics to biomedical devices."
The technique was published on January 13th, 2010, in the journal Nano Letters. The research was sponsored by the Defense Advanced Research Projects Agency (DARPA).
Donna McKinney | EurekAlert!
Nagoya physicists resolve long-standing mystery of structure-less transition
21.08.2017 | Nagoya University
Scientists from the MSU studied new liquid-crystalline photochrom
21.08.2017 | Lomonosov Moscow State University
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
21.08.2017 | Materials Sciences
21.08.2017 | Health and Medicine
21.08.2017 | Materials Sciences